LiFePO4 batteries are becoming more and more common for use in powering astronomy equipment either in the field at a dark site where no power is available or in a remote observatory with only solar power. There are many very good LiFePO4 batteries on the market and I have reviewed two of them on this Blog page previously: Battleborn's 100Ah and Bioenno Power's 50Ah batteries. While both of these are very good options, they are on the expensive side, costing ~$8.7 and ~$10.8 per Ah, respectively. So I
searched for another option with a much better price point and found Ampere Time's 100Ah LiFePO4 battery which sells for ~$4 to $4.7 per Ah. Ampere Time also makes 200Ah, 300Ah batteries for even less per Ah and a smaller 50Ah for ~$5.8 per Ah. With a cost of half the other two batteries and many excellent on line reviews the Ampere Time battery caught my attention. So I contacted them and they agreed to send one of their 100Ah batteries to me to test.
The Ampere Time 100Ah battery weighs only 22.25lbs which is nearly 1/3 the total weight of a 100Ah lead acid battery making it much easier to carry back and forth out into the field or even just the back yard, especially with the included strap. The 100Ah battery is 13" long x 6.82" deep x 8.48" tall which is similar in size to any other 100Ah battery. The battery is expected to have a 10 year life and provide 4000 or more full discharge cycles. It also comes with a 5 year warranty and Ampere Time claims they will respond to questions and service requests within 24hrs although I have not verified this myself. The battery includes the best documentation for operation and care of any of the three batteries I have tested.
Since this is a Li battery it comes with a Battery Management System (BMS) which is internal to the battery case itself. The BMS works in the background to monitor the individual lithium cells and make sure that the battery is operated in a safe mode at all times. It provides protection from short circuits, over current, over charging and over discharging. The later means that one can safely fully discharge the battery at which point the BMS will shut down the output. While considered "fully discharged" there is still sufficient voltage on the internal cells to avoid damage and maintain the projected useable life of 4000 or more such full discharges. Operating temperatures are -4 deg F to 140 deg F (-20C to 60C ) for discharging and 32 deg F to 122 deg F (0C to 50C) for charging, which is typical of most LiFePO4 batteries on the market. It should be noted that unlike the other LiFePO4 batteries I reviewed, this Ampere Time battery does not have a low temperature sensor to automatically prevent charging or discharging below the lower temperature limit. This means that the BMS cannot protect the internal cells from damage if one attempts to charge the battery below 32 deg F or discharge it below -4 deg F. However, for astronomy applications I think it is very doubtful that we would be in a situation where we would attempt to recharge the battery when the temperature is below 32 deg F and most do not work in temperatures below -4 deg either. While an unlikely scenario, if one has the need to recharge below freezing Ampere Time makes a battery with an internal self heater that allows charging down to -4deg F.
Inside the Battery
Besides the low cost of this battery the other reason I decided to review it was the tear down video on Ampere Time's 50Ah battery by Will Prowse which shows the internal components (Li cells, BMS, Wire Gauge, etc.) and build quality to be quite good. I recommend anyone interested in an Ampere Time battery to take a look at that video. The tear down also shows that Ampere Time uses prismatic cells instead of the cylindrical cells used by Battleborn and Bioenno Power. Because prismatic cells are larger and have greater capacity than cylindrical cells only 4 cells are needed to achieve the 100Ah capacity compared to the 120 cylindrical cells found in the 100Ah Battleborn battery. The four prismatic cells are arranged in series with each cell having a nominal voltage of 3.2V and a capacity of 100Ah. In this configuration a nominal voltage of 12.8V is obtained. While less cells has its obvious advantages, damage to a single cell will result in a drop in the voltage making the battery no longer useable. In contrast, damage to a few cylindrical cells in the Battleborn battery may hardly be noticed by the user.
Capacity and Discharge Voltage Tests
The first test of any battery that I review is a full discharge capacity test. Since these types of batteries are shipped with less than a full charge the battery must first be charged to full capacity. I used a 10A AC charger from Bioenno Power designed for lithium batteries to fully charge the battery. Next, I used a battery capacity tester from MakerHawk to measure the actual full discharge capacity of the battery to compare to its manufacturer's spec. I used a discharge current of 5A which is equivalent to ~65W since most typical astronomy setups will use less than this and the ones which use more will not be much more. Once fully discharged I repeated the process to check for consistency. The results were 102.8Ah for the first discharge and 103.1Ah for the second discharge. These are equivalent to 1307Wh and 1314Wh, respectively. So the results from both tests are consistent and show that the battery exceeds its specification of 100Ah by ~3%.
Now, while the full capacity is important, the voltage drop off versus capacity is even more important since some equipment will not work properly if the voltage drops too much below 12V. So I captured the voltage versus capacity data during the discharge tests and this data is shown in the graph above. The average of both tests showed that the battery maintained its voltage above 12.0V for 98.5Ah or 1262Wh which is excellent compared to other batteries I tested or am aware of. By comparison the voltage of a typical lead acid battery drops below 12.0V at ~44% SOC. This means that you will get twice the capacity of a typical lead acid battery with this Ampere Time battery without risking damage to the battery.
There are multiple ways to recharge a battery and I tested the two most common. First, using the above mentioned 10A AC charger I was able to fully recharge a depleted battery in 10.5 hours. This matches very well the measured capacity of 103Ah and the fact that the charger is supplying 10A. Now there are higher capacity AC chargers like the 20A charger from Ampere Time or the much cheaper 20A charger from Expert Power which will charge the battery in half that time if desired.
Out in the field we usually do not have access to AC power so we cannot use the AC charger to recharge the battery. In that case, the battery can easily be recharged with one or more solar panels and a solar charge controller. I used a pair of 100W solar panels from Jackery connected to the battery through a 20A solar charge controller from Bioenno Power. It is important to make sure that the solar charge controller is programed for a Li battery with the correct charge profile and voltages. With this setup, I was able to fully recharge the fully discharged battery in less than 11 hours on a sunny day. The two 100W panels supplied 11A during the bulk of that time while the sun was high in the sky. The charging current obviously falls off quickly as the sun gets lower in the sky. Now, one will not always have 11 hours of sunlight available but the battery reached 84% of full charge in just 8 hours. Also, It is likely not necessary to fully recharge a 100Ah battery during the day since typical astronomy power draws are 60W or less which would only use half the battery capacity over a 10 hour long night. So using a strategy of topping off the battery during the day one could run indefinitely so long as the days are sunny.
Typical Astronomy Use Tests
Before taking the battery out to a dark site I first set it up to power my astrophotography/EAA setup at my home observatory over a period of a month. My home setup includes a Celestron 11" Edge SCT, a Software Bisque MX mount, an ASI1600MC uncooled imaging camera, an ASI224MC guide camera, a Celestron Motorized focuser, a Pegasus Pocket PowerBox Advanced Power/USB Hub, a Beelink Mini-PC, a GL-iNET GL-AR750S-EXT wireless router and a Dell 15.4" laptop. Power was supplied directly to the Pegasus which then powered the MX and the Beelink. The cameras and focuser drew power from the MX while the router drew power from the Beelink. I connect from the laptop to the mini-pc through the wireless router from inside my house where I was able to power the laptop separately with house AC.
Since the Ampere Time battery does not come with cables I needed to make my own to connect from the battery terminals to the Pegasus. I made a pair of 12 gauge cables with lug nuts on one end to connect to the battery and Anderson Power Pole connectors on the other end. Since the Pegasus uses the standard 5.5mm x 2.1mm connectors I made a cable with 5.5mm x 2.1mm connectors on one end to Anderson Power Pole connectors on the other end to connect the battery to the Pegasus. I prefer the Anderson Power Pole connectors wherever I can use them as they make a solid connection which is not easily dislodged in the dark. I prefer the genuine Anderson Power Poles compared the slightly less expensive imitations made in China. If you make your own you will need a crimping tool and the proper gauge wire for your current. This silicone wire will remain flexible in cold weather. If you do not want to make your own cables you can always buy one like this.
Running in my home observatory I encountered no issues with the Ampere Time battery. All told, the load on the Ampere Time battery was ~30W so I was able to run many nights before I needed to recharge the battery.
The final test was a field test at a dark site over multiple nights of astrophotography. For this setup I had all of the equipment mentioned above ( Celestron 11" Edge, ASI1600MC uncooled camera, Celestron motorized focuser, Pegasus Power Box Advanced, Beelink Mini-PC, GL-iNET GL-AR750S-EXT wireless router) but this time mounted on my travel mount, a Software Bisque MyT mount. Also, because I was using Hyperstar no guide camera was needed. But, because of significant dew I has to turn on the dew heater. In this configuration the power load was 52 watts over each of 3 nights. I did not recharge during the day and used a total of 60Ah (784Wh) in 15 hours over the 3 nights leaving me with 40Ah capacity remaining in the battery. That means that I could have run for another 10 hours for a total of 25 hours at my consumption rate before needing to recharge the battery.
Now everyone has a different setup and a different power consumption. For instance, a cooled camera can add another 10 to 20W of power required depending upon the depth of cooling bringing the total power needed to 62W to 72W. That would still have allowed over 17 hours of run time before a recharge would be necessary. Also, if using a laptop directly connected to the setup instead of a mini-pc the power load could be as high as 100W. Even then, the Ampere Time 100Ah battery could supply all the power needed for a full 10 hours which would likely necessitate recharging during the day to enable multiple nights in the field. Regardless of your power requirements, the Ampere Time battery seems to be up to the challenge.
Overall I found that the Ampere Time 100Ah battery delivered the full capacity promised, is very light weight especially compared to a 100Ah lead acid battery and was straight forward to use and re-charge. Obviously I cannot comment on the long term reliability of this battery or any other manufacturer's battery through the simple tests I have available and testing only one battery. But I have no reason after having used it and checking out other reviews to expect it to be problematic. After my tests I even recommended this battery to my friend to replace the AGM batteries in his RV who purchased 3 of these and already installed them and tested them out when he joined me on my field tests.
What I like about the Ampere Time 100Ah battery:
1. It is one of lowest cost LiFePO4 batteries on the market with an excellent reputation.
2. At 103Ah capacity it exceeded its 100Ah specification.
3. It comes with the best care, use and charging instructions of any battery I have tested.
4. They claim 24hr response from their technical support team.
5. It comes with a convenient carry strap.
What I do not like:
1. No US based support hot line. Support is obtained either on line or by calling their number in Hong Kong.
So, if you are looking for one of the least expensive of the LiFePO4 batteries on the market, you should seriously consider Ampere Time. I was not paid by Ampere Time for this review nor did they have any input to it but they did send the battery at my request and at no charge to me.
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This past summer I had the opportunity to stop at the Battleborn factory in Reno, NV on my way back from 3 nights of astrophotography at a northern CA dark site. The folks at Battleborn were nice enough to give me a factory tour and answer many of my questions about their batteries. I decided to visit because I became impressed with the company and their lithium batteries from my prior research. At my request, they sent one of their 100Ah batteries to me to try out as a power source for my astronomy equipment on my next trips out into the field.
Battleborn makes a line of different capacity LiFePO4 batteries which they sell under the parent company name Dragonfly Energy to OEMS like RV manufacturers. They sell the same batteries to the public with a different color casing under the brand name Battleborn. They are a US company which designs, assembles and tests their batteries here in the US. While many of the components are sourced from outside the US, including the lithium cells inside which are only made in Asia at this point, the components are built to their own particular specifications. Unlike most of the Chinese batteries found on line, the folks at Battleborn can be easily reached on the telephone for technical support and service. And, you can even stop by the factory I did if you are passing through the Reno area, but call ahead first.
The 100Ah battery I received weights 31lbs and is sized similarly to any 100Ah lead acid battery weighing more than twice as much. Because this is a lithium battery with a battery management system (BMS) inside it is capable of supply the full 100Ah capacity for 3000 - 5000 full discharge cycles. This compares to the typical 100Ah lead acid battery which is only capable of suppling 50Ah without damage to the internal cells for up to 450 cycles. The Battleborn battery is designed and warranted for a 10 year service life.
As discussed in previous blogs, the BMS is an internal controller whose function is to protect the cells inside from unsafe operating conditions which includes:
1. High/Low Voltage Protection
2. Short Circuit Protection
3. High/Low Temperature Protection
4. Cold Charging Protection
5. Automatic Cell Balancing
This battery can be used to supply power at low and high temperatures given its discharge temperature range of -4°F (-20°C) to 135°F (57.2°C) Like all lithium batteries, it cannot be recharged at a temperature much below freezing given its charge temperature range of 25°F (-3°C) to 135°F (57.2°C). The battery has internal temperature sensors so that the BMS will prevent charge or discharging outside of the allowable range.
Inside a Battleborn Battery
It is worth looking inside any battery that you would consider buying to understand both the quality of components and build process. Unfortunately, this is not something we can typically do but there are YouTube videos showing the teardown of the Battleborn battery and some of the others as well. Here is one from Will Prowse from which I was able to grab a few images for this blog. In this video you can see the excellent build quality and components which can be contrasted with another vendor which is not of very high quality.
Looking inside the Battleborn one can see that it uses cyclindrical cells which are the most common cell type found in lithium batteries at this point since they are more amenable to automated manufacturing processes. This makes them less expensive and provides for consistent build quality from cell to cell. You can also see that the cells are arranged in 4 groups in series of 30 cells each in parallel for a total of 120 individual cells. The cells in parallel provide the voltage ( 4 x 3.2 to 3.3V = 12.8 to 13.2 V). The 30 cells in series provides the overall capacity (30 x ~3.4 to 3.5Ah = 102 to 105Ah ).
Capacity and Discharge Voltage Tests
I performed extensive testing of the Battleborn 100Ah battery both at home and in the field on two different dark site trips. The results of these tests are summarized here. The first test was a capacity test to see if the battery delivers its rated Ah. Three full discharge cycles were performed using a 90W, 60W and 60W load. A typical astronomy setup might use between 30W and 60W with 90W being a very high power case. Regardless, these loads are very small compared to the battery's 100A maximum current capacity so, not surprisingly, the measured capacity remained constant within 1Ah across all three tests with an average capacity of 110.5Ah. Considering that the voltage drops, especially during the last 10% of capacity, a more relevant number is the capacity at 12.0V which was 105.5Ah. This is in line with the fact that Battleborn overbuilds their batteries using cells packs measured during test and assembly to be between 104 and 108Ah. I was actually able to see the capacity markings on the sides of the cell packs before final assembly which are used to balance the final capacity within their manufacturing tolerance of 104 to 108Ah.
Next, is the voltage drop off with the state of charge (SOC). Since LiFePO4 cells have a voltage of 3.2 to 3.3V and are combined with 4 packs in series, the initial voltage of a fully charged battery will be between 12.8V and 13.2V. The discharge curve which I measured below shows that the initial voltage under load was 12.9V and that the voltage remained above 12.0V until 96% of the total capacity was consumed which is the 105.5Ah number stated above. The voltage curve was the same for a 60W load as it was for a 90W load. In contrast, a typical lead acid voltage curve also shown indicates that the voltage drops below 12.06V at 50% SOC which is the minimum SOC to avoid damage to the cells. For comparison only, a lead acid battery drops below 12.0V at ~44% SOC.
I was able to take the battery with me to the Calstar star party in California for 4 nights under the stars. It was nice to only have to carry a single 31lb battery rather than my usual 63lb lead acid battery, or even 2 of those if I could not recharge during the day. My setup included a Software Bisque MyT mount, an ASI1600MC uncooled imaging camera, an ASI224MC guide camera, a Celestron Motorized focuser, a Pegasus Pocket PowerBox Advanced Power/USB Hub, a Beelink Mini-PC, a GL-iNET GL-AR750S-EXT wireless router and a Dell 15.4" laptop. Power was supplied directly to the Pegasus which then powered the MyT and the Beelink. The cameras and focuser drew power from the MyT while the router drew power from the Beelink. Because my Dell laptop can only use AC power from its AC adapter, I used a 300W Inverter attached to the Battleborn to provide the AC power to the laptop.
The Pegasus Powerbox Advanced has an internal power meter which allowed me to monitor the power to everything except the laptop. I used an in-line power meter to keep track of the power consumed by the inverter/laptop. The net power for everything was 63.2W with 41.6W going to the Pegasus and 21.6W going to the inverter. The Beelink ran The Sky X which controlled everything (cameras, focuser, imaging) while the laptop was used as a remote control by connecting to the Beelink through the router using Team Viewer. This explains the low power consumption by the laptop.
The first night I did my TPoint model, Polar Alignment and imaged, running for a total of 7 hours using 32.85Ah (432Wh), or 31% of the Battleborn's 105.5Ah measured 12.0V or higher capacity. On the second night I imaged for 5hrs and 20min before turning in and used an additional 25.9Ah for a net of 56% of the total capacity. The third night was a bust due to high winds, but I was able to image for 6 hrs and 20min on the fourth night using another 31.48Ah. Adding these up, I ran for a total of 18.5hrs and consumed 86% of the battery capacity which indicates that the maximum run time is 21.5hrs for a 63W load without a need for a recharge.
Everyone's power consumption will be different from mine so I put together a table with three different power ranges to provide estimates of run times with the Battleborn 100Ah battery. Because one can use the full capacity of this battery, it provides seriously long run times without a re-charge and obviously longer with a re-charge in the field.
While I was able to run my setup for three nights without a re-charge, there will be times when I am imaging for longer periods each night, running a heavier load or spending more nights under the stars. In those cases I will want to re-charge the battery during the day.
If one has access to AC power during the day, an AC charger designed for lithium batteries can be used to top off the battery. I used this 10A charger from Bioenno Power to recharge from a complete discharge to fully charged in 11 hours. The nice thing about lithium batteries is that they can take a higher charge current than a lead acid battery. The Battleborn spec indicates 0.5C or 50A maximum. Even a 20A lithium charger like this one would recharge the battery fully in 5hrs. Also, it is unlikely that one could fully discharge the battery in one night anyway so a 20A charger is probably more than sufficient to top off the energy used during the previous night.
In most cases, we do not have access to AC power during the day which is why we carry a battery with us in the first place. For this situation solar panels along with a solar charge controller are required. You will have to add a pair of wires to connect from the solar panel to the charge controller and from the charge controller to the battery. Always connect the battery first and the solar panel last. In my case, I used these pre-made Power Pole Adapters from Bioenno, but you can make your own cables with Power Pole connectors, a crimper and zip cord from West Mountain Radio. You can get all of the components needed from any number of suppliers on Amazon for less, but I have found that the genuine Anderson Power Poles work best.
In the first solar recharge test I used a 100W Bioenno solar panel along with a Bioenno charge controller with full sun. This setup recharged the battery from fully discharged to fully charged in 20hrs as the average current supplied to the battery was a little over 5A. The math works as it should (5A x 20hrs = 100 Ah). Obviously, we do not get 20hrs of sunshine during the day but since it is unlikely that one would have to fully recharge the battery after a single night's use a 100W solar panel should provide at least 6hrs of re-charge time or roughly 30Ah which would have topped off the battery after one of my typical nights usage.
Clearly more solar panels will re-charge the battery faster, so in the second test I used two 100W Jackery Solar Panels in parallel along with the same Bioenno charge controller to recharge the battery. With two panels supplying 11.3A of charging current, I was able to fully recharge the Battleborn in 9.75hrs. So, if you want to be certain to have sufficient charging power to fully recharge the battery if you are using more than ~30Ah a night, a second 100W panel will be necessary.
The Battleborn 100Ah LiFePO4 battery met all of my expectations and even exceeded its capacity spec by 5%. This battery packs a lot of energy into a small light weight design and can easily supply power for most astronomy setups for multiple nights on a single charge. For larger power requirements you will need to invest in solar charging equipment to re-charge during the day or have access to AC power to use one of the lithium based AC chargers.
What I like about the Battleborn 100Ah Battery:
1. Designed and manufactured in the US
2. US sales and technical support
3. Delivers 105% of its rated capacity at 12.0V or higher
4. Uses cyclindrical cells
4. Unheard of 10 year warranty
What I do not like:
1. At $799 from the factory the Battleborn battery is still one of the most expensive LiFePO4 batteries compared to some of the Chinese brands like Ampertime, Chins and Zooms who all use prismatic cells instead of cyclindrical cells. And, all three of those based upon tear down videos look like they are built in the same Chinese factory although they are sold under different brand names.www.youtube.com/watch?v=4yu4Ei1-2jA&t=1s
So it comes down to whether or not you are looking for the cheapest option, or a good battery with US support that is easy to reach if you need it.
Amazon links are Associate links from which I can earn commissions at not cost to you.
Edit: I have created a video version of this review which you can find here on YouTube
Having previously tested and reviewed lithium powered solar generators from Jackery and Bluetti I wanted to test a simple lithium battery as an alternative power solution when in the field. Solar generators are convenient as they come with all of the power ports, a display, power meter, AC inverters, etc. But not everyone needs all of that in which case a stand alone lithium battery may be the better solution. Fortunately, the folks at Bioenno Power were kind enough to send one of their 50Ah LiFePO4 batteries to me to test along with one of their 100W solar panels, a solar charge controller and a 10A lithium AC charger.
The first thing to note about Bioenno Power is that they are located in Santa Ana, California and can be easily reached on the telephone for sales and technical support. That is how I reached the owner, Kevin, who advised me on the equipment that I would need. Like most other lithium power suppliers, Bioenno Power products are manufactured in China, but tested at and distributed from their facility in California.
Bioenno Power sells a wide range of lithium battery capacities from 3Ah to 300Ah. The 50Ah battery I got comes with integrated Anderson Power Pole connectors which made it easy to connect to my Power Distribution Hub with a simple adapter cable which converts from Power Pole to 5.5mm x 2.1mm connectors. If you do not like the Power Pole cable you can simply add your own cable like you would on any other battery. If you prefer, you can even use a Power Pole to Cigarette socket cable. The battery is compact with dimensions of 8.4" (L) x 4.3" (w) x 5.8" (H). It weighs only 13.3lbs. and has an integrated plastic carrying strap which makes it a breeze to transport back and forth into the field. It is rated for >2000 charge cycles which is typical of LiFePO4 batteries.
Like all lithium batteries, this one has an internal module, which they call the Protection Circuit Module (PCM) to provide overall protection from unsafe operating conditions such as low and high temperature charging, short circuits, overvoltage, etc. It also has the responsibility to balance the individual cells inside so that no cell gets discharged before the others. It sounds like their PCM is just what the industry typically calls a Battery Management System or BMS. One of the great this about a BMS is it allows the battery to supply the full capacity (100%) without damaging the individual cells inside in contrast with a lead acid battery which should be re-charged once it has depleted 50% of its capacity. The PCM (BMS) will shut the battery down to prevent the individual cells inside from being damaged when they reach a minimum voltage.
Capacity & Discharge Voltage Tests
Like most LiFePO4 batteries, the Bioenno battery uses cylindrical LiFePO4 cells which have a nominal voltage of 3.6 to 3.7V. Multiple cells are connected in parallel banks to supply the rated Ah or Wh capacity and then 4 of the banks are connected in series to give the nominal full charge voltage of 12.8 to 13.2V. Thus, the number of cells in the battery is determined by the Ah rating of the individual cells which indicates that this battery has 4 stacks in series of 16 cells in parallel for 64 cells total.
My first test was full discharge capacity test to see how the battery compared against its manufacturer's spec of 50Ah, or 640Wh. I used a constant 65w load which is representative of a typical astroimaging setup with a dew heater and cooled camera. This is a little over 5A, or 1/10 C which means it is not stressing the battery which is designed to deliver 1C, or 50A in 1 hour. The test was performed 3 times and the results were very consistent providing 47.6Ah (606Wh) which is 95% of the rated capacity of 50Ah. That is well within their specs and typical for lithium batteries where the BMS (PCM) shuts the battery down to reserve power to keep the BMS functioning for the battery re-charge cycle.
The discharge curve voltage shows that the battery voltage stays above 12.0V through 91% of its rated capacity of 50Ah (96% of my measured capacity of 47.6Ah). This slow voltage roll-off is one of the advantages of Li batteries compared to lead acid which drops below 12.0V just below 50% capacity.
After initial testing of the battery on my setup at home, I took it with me to a dark site for three nights under the stars. I used the Anderson Power Pole leads from the battery to connect to an in-line power meter which kept track of the number of Ah and Wh used so that I could match that against the capacity I had measured to keep track of the remaining capacity after a night's use. The output of the power meter feeds into my Pegasus Power Box Advanced (PPBA) which then feeds power to the rest of my equipment. The PPBA has its own internal power meter so, in my case, I did not actually need the external power meter but chose to use it to show those who do not have the Pegasus how to measure the power used with an inexpensive (~$15) meter.
The Bioenno Power battery supplied power to the entire setup which included:
1. Pegasus Power Box Advanced Power/USB Hub
2. 12V to 48V DC-DC converter for power to the MyT mount
3. ASI1600 guide uncooled camera - powered through the mount
4. ASI224MC guide camera - powered through the mount
5. Celestron Motorized focuser - powered through the mount
6. Cooling fans for the Celestron C11 SCT - powered through the mount
7. Beelink U57 Mini-PC
8. GL.iNET AR750 portable wireless router
The Beelink controlled everything using The Sky X including guiding and imaging. I connected wirelessly over the GL.iNET WiFi to the Beelink with my Dell 15.4" laptop to monitor activity, but the laptop was powered by a separate power supply for this set of tests. The average power draw with this setup was only 30W, which is representative of many typical setups with uncooled cameras and no dew heater. We will discuss more power hungry setups below. I was able to image for 2 nights (3rd night was a bust for other reasons) for a total of just under 12 hours. Based upon my initial capacity measurement and the in-line watt meter, 57% of the capacity was used over that period. That means that the Bioenno battery could last for just over 20hrs at 30W without a re-charge.
Now my setup did not include a cooled camera nor a dew heater which are very common and can draw between 10 and 20W each, on average. Also, if I had used my Dell laptop to run everything, the total power consumed would be much higher. To address these situations, I performed measurements of the power draw for these additional equipment and put together a table with 3 increasingly power hungry setups to estimate the run time for this Bioenno 50Ah battery for each setup. From that, you can estimate the run time for your particular setup as well. As you can see from the table, adding a dew heater and camera cooling can drive the power consumption up to 60W or slightly more. In that case, this battery would last for one long night or two shorter nights without the need to re-charge. If one needs to use the power hungry laptop instead of a Raspberry Pi or mini-pc, 50Ah may not be sufficient capacity. This leads us to the question of re-charging the Bioenno battery.
There are two basic ways to re-charge a lithium battery; 1) with an AC charger designed for lithium batteries; 2) with a solar panel(s) and a solar charge controller. You can get a 10A, 15A or 20A charger from Bioenno which has Anderson Power Pole connectors to conveniently connect to the battery. They sent their 10A charger to me which is very simple to use. Just connect the Power Pole connectors to the battery and plug in the charger. Since it is already set for lithium batteries it will use the correct charging cycle and shut itself off when completed. In my case, I was able to re-charge from 0% SOC to 100% SOC in 4.7hrs. The higher amperage chargers will charge in correspondingly shorter times.
Since we do not always have access to AC power in the field, we usually need to use a solar panel to recharge a battery. I recharged the Bioenno battery with 2 different 100W solar panels, one each from Jackery and Bioenno. When charging a stand alone battery with a solar panel, a solar charge controller is required such as this 30A MPPT controller that Bioenno sent to me. To use it, you will have to add a pair of wires to connect from the solar panel to the charge controller and from the charge controller to the battery. Always connect the battery first and the solar panel last. In my case, I used these pre-made Power Pole Adapters from Bioenno, but you can make your own cableswith Power Pole connectors, a crimper and zip cord from West Mountain Radio. You can get all of the components needed from any number of suppliers on Amazon for less, but I have found that the genuine Anderson Power Poles work best.
Both panels were able to re-charge the battery in 8hrs with full sun. The Jackery is an extremely well designed bi-fold panel which I previously reviewed here. But at $300 it is more expensive than the Bioenno panel at $210 and requires an 8mm to Anderson Power Pole Adapter which are difficult to find. The Bioenno panel is also well designed, folds out into 4 segments for a smaller footprint, and comes with a 50A Power Pole connector. The later means that you will need a 50A to 45A Power Pole adapter cable to connect the solar panel to the charge controller.
The Bioenno Power 50Ah LiFePO4 battery performed well both at home and out in the field as expected. Because of it's small form factor and light weight, the Bioenno battery works well for someone needing 30W or less for 2 or 3 nights in the field without the need to recharge. For larger power requirements you will need to invest in solar charging equipment to re-charge during the day if you want to run for multiple nights in the field.
What I like about the Bioenno Power 50Ah Battery:
1. US sales and technical support
2. Delivers 91% of its rated capacity at 12.0V or higher
3. Small, lightweight form factor
4. Comes with Anderson Power Pole cables
5. 2 year warranty and 30 day return policy
What I do not like:
1. $470 for 50Ah is expensive compared to some of the Chinese brands like Ampertime, but not compared to other US based retailers like Battleborn and Dakota lithium.
So it comes down to whether or not you are looking for the cheapest option, or a good battery with US support that is easy to reach if you need it.
I was not paid by Bioenno for this review nor did they have any input to it but they did send the equipment at my request and at no charge to me.
Amazon links are associate links from which I can earn a commission.
Edit: You can find a video version of my Bioenno Power battery review on my YouTube Channel
Last November I reviewed the Jackery Explorer 1000 solar generator on this web site: www.californiaskys.com/blog/archives/11-2020 (scroll down below the solar panel review) The Explorer 1000 packs almost 1000Wh of power into a compact and rugged design weighing only 22lbs making it well suited to multiple nights of astro-imaging without the need to recharge. But not everyone needs that much power or cannot afford to pay $1000 ($880 on sale) for their power supply. So, I got hold of Maxoak's Bluetti AC50s which is a 500Wh model costing only $400 ($380 on sale) to run through the same set of tests to evaluate its usefulness as an astronomy power supply in the field. In short, the AC50s worked well over multiple nights in the field.
Let's first start with a run down of the AC50s' included accessories and then its features. The generator comes with an AC charger, a car charging cable, an MC4 cable to use when charging with a solar panel, a USB Type C extension cable, a decent user manual and a 24 month warranty. Unlike the Jackery, a carrying case for the accessories is not included. The AC50s is well built with a rigid ABS plastic casing, very compact at 11.6 x 7.7 x 7.5 in. (L x W x D) and extremely light weight at 13.6lbs. It has fold down handles which makes it easy to carry around and store. Most everything one needs to access is conveniently located on the front of the generator including:
1) a regulated 10A DC cigarette adapter socket with dust cap
2) two unregulated 3A DC 5.5mm x 2.1mm ports
3) a 45W PD type C charging port
3) four USB A 5V/3A ports
4) two 110V AC outputs from the internal 300w pure sine wave inverter
5) an LCD display showing DC/AC power output, charging input power and battery State of Charge (SOC) in 20% increments
6) On/Off buttons for the power outputs and the display
This generator also has a 10W magnetic charging port for phones equipped with magnetic charging capability located on its flat top. On the backside you will find an 8mm port for the internal MPPT charge controller used to re-charge the generator either with the included AC charger or an optional solar panel. There you will also find a large white LED light. This light is much more useful than the small LED spotlight on the Jackery for illuminating a large area.
As noted above, a major convenience of solar generators is the inclusion of a pure sine wave inverter to supply AC power for any devices being powered with an AC wall charger like a laptop. At 300W the AC50s' inverter will easily power all of our astronomy equipment if we so choose. Also, the internal MPPT charge controller eliminates the need for an external charge controller when recharging the generator. Simply connect the solar panel output with the appropriate cables to the 8mm charging input of the solar generator. Always keep any lithium battery shielded from the sun when charging with a solar panel. I like to use the panel itself to shade the lithium power supply.
Just like with the Jackery Explorer 1000, I ran a series of tests of the AC50s both at home and in the field powering my Software Bisque MyT mount, Celestron C11 OTA, Celestron focuser, ASI1600MC camera, ASI224MC guide camera, TEMP-est cooling fans, mini-PC and a Pegasus Power Box Advanced (PPBA). I used a cigarette adapter to 5.5mm x 2.1mm cable to supply power from the AC50s to the PPBA which in turn distributed power to the MyT. The cameras, focuser and fans drew their power from the MyT. Since the MyT requires 48V I used a DC-DC up converter on the output of the PPBA to transform 12V to 48V rather than using the less efficient AC adapter. I use The Sky X (TSX) to control everything except the PPBA which is controlled by its own application.
First, I measured the total energy capacity of the AC50s by running the generator from 100% to 0% SOC multiple times. Yes, with lithium based power supplies you can safely run them down to 0% SOC quite unlike a lead acid battery which should never be drained below 50% SOC to avoid permanent damage. In the case of lithium batteries, an internal battery management system (BMS) functions to protect the battery from all manner of unsafe operating conditions. This includes over-voltage, shorts, charging below freezing, charging/discharging above 104 degrees F, over-charging and over-discharging the individual lithium cells inside. All lithium batteries with an internal BMS, this includes solar generators, are designed to be discharged to the point where the BMS shuts the output down to avoid dropping the voltage of the internal lithium cells below the voltage where permanent damage may occur. Thus, these solar generators can use 100% of their SOC without damage to the internal cells while maintaining the manufacturer's full discharge cycle spec. In the case of the AC50s, it is spec'd to 1000+ full discharge cycles at which point it's capacity will be reduced to ~ 70 to 80% of the original capacity. That will provide energy to run a setup more than 100 nights a year over the 10 year expected lifetime of the generator. The results of my capacity measurements produced an average of 461Wh or 92% of the rated capacity, which is in agreement with another on line review I have seen, and is similar to what I found for the Jackery Exporer 1000. Not surprisingly, some power is lost in the regulation circuit, etc.
After each full discharge test I was able to make measurements of the recharge times using both the supplied AC charger and a 100W solar panel. I made repeated tests for each method. It took between 7 and 7.5 hours to recharge the generator using the AC charger while it took only 6 to 6.5 hours to recharge using the 100W solar panel. The faster charging rate with the solar panel occurs because the AC charger supplies ~ 82W while the solar panel supplied 95W of input power, hence the faster charge time with the solar panel.
Now the most important question is "How long with the AC50s be able to power your astro rig?". That, of course, depends upon what is included in your particular rig. After verifying that the AC50s powered all of my equipment over many nights in my home observatory without any issues, I took it into the field for 3 nights under the stars with the setup described above:
1. Software Bisque MyT mount
2. ASI1600 MC uncooled camera
3. ASI224MC guide camera
4. Beelink Mini-PC
5. Pegasus Astro PowerBox Advanced
6. TEMP-est cooling fans
7. Celestron Focuser
The cameras, cooler fans and focuser all drew power from the MyT Versa-Plate power connections. The mount and mini-PC were connected directly to the PowerBox which was itself powered directly from the AC50s through the 10A regulated cigarette port.
The first night using the guider, my setup drew an average of 35W per hour over 6hrs for a total of 210Wh leaving the AC50s with 60% SOC at the end of the night. During the next day, I used a 100W solar panel to re-charge the generator to 100% SOC in just a few hours. Over the next 2 nights I ran without guiding, averaging 29W of power for 7 hours the first night and 5 more hours the second night without re-charging in between. Thus, after 12 hours I had used 352Wh, or 76% of the measured total capacity, leaving me with 3.75 hrs more run time at 29W. Overall, the Bluetti AC50s performed flawlessly as expected.
Now, there are setups which require more than ~30W of power. From my own measurements here www.californiaskys.com/blog/archives/11-2020, adding a dew heater for the C11 at full power requires 20W additional power and Peltier cooling for a camera will also add ~20W at maximum power. That would push the power requirements of the above setup to ~70W. At that consumption, expect the AC50s to last for 6.6hrs. You can estimate your power consumption by scaling my numbers to your typical use conditions. I believe typical power consumption falls into one of 3 ranges: 1) 20-30W; 2) 30 - 60W; 3) 60 - 90W. Likely most fall into either range 1 or 2 and only those using a laptop to control their setup along with significant dew control and camera cooling will require as much power as indicated for range 3. If we divide the measured maximum capacity of 461Wh by 30W, 60W and 90W we can estimate run times of 15.3hrs, 7.7hrs and 3.8hrs. If your needs fall within category 1 the Bluetti AC50s will likely support 2 nights of imaging without a recharge, but if you fall within category 2 you will need some way to recharge during the day to obtain multiple nights in the field. If your needs fall into category 3, you will need a solar generator rated with a much higher capacity like the Jackery Exporer 1000.
In summary, the Maxoak Bluetti AC50s 500Wh solar generator is well designed, simple to use and easy to carry about. It sure beats lugging a 64lb 100Ah lead acid battery to provide the same amount of energy and comes with all of the power connections and additional features designed in.
You can find more content on Solar Generators, etc. on my YouTube Channel.
Amazon links are associate links from which I can earn a commission.
After years of sleeping first in a tent and then in the back of my van at star parties and dark sky excursions, I finally decided to go in style with an RV. My plan is to sit inside my nice cozy RV with my laptop and control my telescope, cameras, etc. wirelessly with WiFi. I bought a Beelink U57 mini-pc which sits at the telescope and runs all my software while I remotely log into the mini-pc with my laptop inside the RV. The mini-pc is headless (i.e. has no display to suck power) and therefore draws an order of magnitude less power than the laptop would running the same software. I can use the laptop as a terminal inside the RV and, with proper shielding, be able to view images on the screen unfiltered without disturbing anyone else with the light from my computer. Also, if I need to conserve power I can let the laptop go to sleep as I only need it to check in on the mini-pc's progress if I am doing a long imaging run. If I am doing EAA (camera assisted viewing), I will to use the RV's power to keep the laptop running during a session.
Up till now I set up inside an EZ Up shelter with side curtains and with the pc shielded so that the light is minimized. I use a 32ft active USB3.0 cable between the scope and the laptop for connectivity. I could do the same with the RV running the cable through a partially open window but I want to minimize the use of cables which are easily tripped over in the dark. Instead I decided to find a portable wireless router which can provide a reliable connection throughout the night from inside my RV to my rig outside. And since I may not always be able to park right next to my scope, the longer the range of the router the better. The router needs to run on dc and require as little power as possible.
So when I read about the GL.iNET GL-MT300N-V2 Wireless Mini Portable Travel Router for less than $20 ($27 these days) I decided to give it a try. At this price I figured there was not much to lose. This mini router is less than 2.5" square and about 1" tall with a bright mango yellow plastic case weighing less than 2 oz.. It has 2 Ethernet ports, 1 USB2.0 port, a Micro USB port for input power and 128Mb of RAM. It uses 5V/1A so it can easily be powered by one of the USB ports on my mini-pc and draws less than a couple of watts of power by my measurements. It comes with an Ethernet cable and a USB2.0 to Micro USB cable which connect to my mini-pc, a Beelink U57 with an Intel Core i5-5257u Processor. It has LED lights to show that it is powered and has a reset button and a mode switch. The GL-MT300N-V2 only supports the 2.4G band at 300Mbps and not the faster 5G band. It can function as a portable router, mobile hot spot, WiFi repeater bridge or range extender. I only need it to function as as a portable router to set up its own WiFi network which I can connect to from my laptop inside my RV.
The setup was simple and straight forward with the included instructions. You simply apply power to the router and it begins broadcasting a WiFi signal. You connect to the WiFi with the default password printed on the bottom of the router which is simple to change once connected. To access the router settings you simply connect to the IP address in the instructions. This will take you through a screen to choose your language, a screen to change your Admin Password and finally to the main page with access to an Internet, Wireless, Clients, Firewall, etc. pages where you can change settings for each of those if desired. For my application using this as a wireless router, the only thing I needed to change was the password. Closing out the connection to the router I was set. Then I simply connected the router to my Beelink mini-pc with the Ethernet cable and powered up the router with the Micro USB cable also connected to the mini-pc. Now I could see the GL-MN300N-V2 WiFi signal on my laptop and connected to it using the password I had just created. To connect between my laptop and the mini-PC I use TeamViewer but you can use Remote Desktop or any other such software.
Since I do not have my RV yet, I set about to test the quality and stability of the wireless connection with the GL-MT300N-V2 connected to my Beelink mini-pc inside my observatory and my laptop setup in the back yard at different distances from the observatory testing the connection at successively longer distances. Once connected, I observed how long it was able to maintain the connection while performing a dummy astrophotography run with the telescope tracking and the camera taking exposures of 1 minute duration while watching progress on my laptop. The objective was to find the maximum distance that a a continuous connection could be confirmed for at least 8hrs. At 75 ft I could not get a connection at all. At 65 ft I could connect to the wireless network but the connection would drop repeatedly. I was able to maintain a solid connection at a distance of 60 ft to the Travel Router inside the observatory without dropping for in tests of up to 8 hours. I repeated this test two more times and satisfied myself that I could reliably maintain a connection through the observatory walls at a distance of 60 ft. In addition to maintaining a solid connection I tried opening files and changing settings in The Sky X (TSX) running on the Beelink mini-pc. At 60 ft I did not see any issues of a sluggish or poor connection. Keep in mind that the quality and stability of the connection depends both upon the Travel Router's wifi strength and also on the strength of the wifi hardware inside my laptop. Other laptops or pcs may support longer or shorter distances than mine. Also while the wooden walls of the observatory are not the same as the fiberglass and aluminum walls of my RV I expect that I will be able to connect reliably to my telescope out in the open at a similar distance. Encouraged by the 60 ft distance I tested the connection from inside my house on a straight line of sight through glass doors to the observatory only 40 ft away. While I could make a connection it would always drop within an hour or less so I deem this unreliable for a connection through a pair of walls or other multiple obstacles.
Although the GL-MT300N-V2 worked well for my application and I think it will serve my needs in the field I wanted to try a slightly more expensive router from the same company equipped with a pair of antennae to presumably provide greater distance capability along with 5G (433Mbps) for faster connection speed. The GL-AR750S-Ext travel router sells for $54.90 and comes with 3 Ethernet ports, a USB2.0 port and a micro USB port for power input. It also has LEDs for power, 2.4Ghz and 5Ghz WiFi signals, 128Mb of RAM, a reset button and a mode button, a micro SD card slot and 2 antennas which can be rotated from the compact travel position to 90 degrees during operation for better signal range. This router is also quite compact with dimensions of 3.9 x 2.7 x 0.9 inches with the antenna folded down and weighing only 3 ounces. It has over 1600 reviews on Amazon with 89% of them rated 4 or 5 and only 7% rated 1 or 2. Setup is the same as for the GL-MT300N-V2.
I performed the same tests as with the GL-MT300N-V2 above. In this case I could reliably connect at a distance of 100 ft from my observatory at 2.4G for repeated tests of 8 hours and longer. 100 ft is the maximum distance I can be from the observatory in my back yard so it is possible this will work at a longer distance. Using the faster 5G connection, although I was able to make and maintain a connection repeatedly at 100 ft for 6 hours or longer, several times I had trouble making the initial connection and multiple times the connection dropped around 6 hours. It is well known that the higher frequency of 5G does not have the range of the lower frequency 2.4G so this is not surprising. The higher frequency signal has more difficulty penetrating walls. Tests from inside my house confirmed that I could not obtain a reliable connection at 5G but could easily maintain a connection all day long at 2.4G. This is at a distance of about 50ft from inside my house to the router inside the observatory. So it is clear that the GL-AR750S-Ext can provide a wireless connection at a greater distance than the GL-MT300N-V2. This is not a surprise since that is obviously the point of the antenna.
I did not test transfer speeds or other performance metrics as I merely want to be able to remotely control the mini-pc and keep an eye on an imaging run with the laptop remotely. I did test downloads of data which worked without a problem over this WiFi network but did not try downloading images as they are captured as that is not my objective.
As I mentioned above, differences in the wifi antenna of the laptop or pc being used, local interference from neighboring wifi signals and even RF interference from electrical equipment like a microwave can change the distance at which a reliable connection can be made and/or cause connection disconnects. As far as my tests, I think either travel router will work well for my application with the GL-AR750S-Ext giving me a greater distance capability. I would recommend either so long as your situation is similar.
Links are Amazon Associate links.
I posted a review of the Jackery 1000Wh solar generator earlier this month with my overall impression being that it is a very well designed and built power supply which can power even the hungriest astronomy setup for 8-10hrs without needing a recharge. While the Jackery can be recharged fastest with an AC outlet using the supplied charging cable, it can also be recharged quickly during the day using Jackery's Solar Saga 100w solar panels. Here I review the results of over a month's testing of a pair of 100w solar panels along with the generator both at my home observatory and during a 3 night trip to a dark site.
Jackery makes two versions of their solar panels, a 60w and a 100w model. While I tested a pair of the 100w models, they share design features with the 60w model as described here with the differences being size, weight and power output. Both panels use Monocrystalline solar cells with up to 23% efficiency and a voltage output of 18V and a current of 5.55A. The panels have over voltage, short circuit and surge protection built in. They have an operating temperature range of 14 deg F to 149 deg F. They come with a 24 month warranty but an included registration card will extend that to 36 months. The 100w panel is 48in x 21in x 0.2in when fully extended to capture the sun's rays. For transport and storage it conveniently folds in half. A pair of magnets cleverly embedded in plastic at two corners of the panel help to keep the panel folded when not in use or during transport. It also has a built in rubber carrying handle and weighs only 9.1lbs. All of these smart design features make it very easy to transport and set up in the field.
Each half of the full panel has a kickstand which stays put with velcro for travel and can be extended to support the panel when charging. The panels have a protective laminate layer for dust and weather resistance. A zippered pouch on the backside holds the 3m charging cable which is hard wired to the panel. The 8mm connector on the other end plugs into the charging port on the Jackery when charging the generator. Each panel also has a 5V 2.4A USB-A and a 5V 3A USB-C charging port on the backside so that a cell phone or tablet can be charged directly from the panel with the proper charging cable. Overall, I am impressed with the quality of the build and cleverness of the design making it easy to use. I give Jackery an A+ for design smarts and convenience.
I ran a series of tests with the 1000Wh solar generator using my typical astrophotography imaging setup over 4 weeks at my home observatory and in a three night field test at a dark site location. In between tests I had multiple occasions to recharge the generator with the pair of 100w solar panels under varying sky conditions including best (full sun) and worst (overcast) case skies along with the in between cases of partial sun and clouds. To use two solar panels a Y adapter cable which is supplied with the 1000Wh generator is used to combine the outputs of both solar panels which are then fed into the generator's input port. It is not absolutely necessary to use both solar panels but the recharging time will be significantly reduced with two panels instead of one. I should point out that all of these took place in late September and early October as we moved into fall and the sun is lower in the sky and the days are roughly 11hrs long.
The first thing I checked was the output of each solar panel. Keep in mind the output power of a solar panel varies with sun intensity and angle of the panel relative to the suns rays. Maximum output is seldom achieved, and when it is it is not sustained over long periods unless you re-align the panel due to changing solar intensity and angle. The meter on the Jackery 1000Wh generator showed that panel #1 was charging at a rate of 87/88w on a sunny day which is well within what other reviews have shown. Next I tested the second panel but its output was only 42/43w. Clearly the second panel was not performing up to spec. I contacted Jackery and they made arrangements for the second panel to be returned to them and a new one sent in its place, but since I was headed to a dark site for new moon in a week I asked them to wait until after my excursion to replace the second panel and forged ahead with the panels I had on hand. On a very sunny day the input to the generator with the pair of panels connected in parallel with the Y adapter cable varied from 118w to 125w over the course of the day as it charged from 20% to 100% in just 7 hrs. This rate of charge says that it should take ~ 8.75hrs to fully recharge the battery from 0% to 100%, which is in line with the advertised time of 8hrs.
Not all days will be sunny so I checked how well the panels worked during several days with very little direct sunlight. The second solar recharge took place during the massive CA wildfires including three of the largest in the state's history very close to my home. With smoke filled hazy skies the entire day, the panels were able to recharge from a SOC of 23% to 100% in approximately 9.5hrs. The input to the solar generator typically read between 80w and 90w for much of the day. Apparently, enough UV light made it through the smoke particles in the sky. I was quite surprised.
For the third solar recharge I picked a day with periods of partial sun, high thin clouds, but mostly a steady overcast condition. The output power of the panels fluctuated from 0w to 122w but hovered mostly around 22-48w throughout the day. In this case the two 100w panels could only provide enough power to recharge the generator from 18% SOC to 67% SOC in 9 hours. The Jackery panels are not unique in this regards as no solar panel can provide much output if the sun doesn't shine. But I was impressed that even under these gloomy skies I was able to recharge the generator by almost 50%. Odds are that if the day is that overcast we would not expect a clear night for astronomy so this would not be a problem.
The charging rate was very linear with the SOC increasing just over 9% per hour of solar exposure up until the final 1% percent. This is nice in that, if the sky conditions are expected to remain fixed throughout the day, one can make a fairly accurate estimate of how long it will take to recharge under different sky conditions.
During my 3 night field trip to do astrophotography during the new moon I had the opportunity to recharge the panels after the first two nights. The first night I spent 8 hours imaging resulting in the generator dropping to 28% SOC. With full sun the next day I was able to fully recharge the generator as well as top off my laptop battery with Jackery's pass through charging option in a bit over 6 hours. Pass through charging allows the generator to be recharged at the same time it is supplying power to a load. The second night I imaged for only 6 hours and was easily able to recharge the generator in less than 6 hours in full sun. With this setup I could have easily imaged 8 hours a night indefinitely, fully recharging the generator, laptop and my cell phone during the day with the solar panels so long as I had ~7 hours of sunshine.
Once I returned from my field trip I returned the under performing panel to Jackery with a prepaid voucher and quickly received a replacement. The first thing I did was to test it against the first panel under fully sunny skies. This time both panels consistently output 96/97w of power in tests on two different sunny days. This is exceptionally high compared to what I have read for any 100w solar panels on the market. Obviously the sun's intensity and angle or both are extremely important to obtaining maximum power output. I could easily improve the output by ~10w carefully adjusting the azimuth and angle of the panels.
Next I checked the output with the pair of panels connected in parallel with the Y adapter. The configuration produced 129w of input power to the generator which remained steady over time. Why not 192W you might ask yourself. If you read my review of the solar generator you will see that with the supplied AC adapter the input power was 164w. Then why the difference with the two 100w panels? Well, I read in one review that the Jackery limits the total input current and since the AC adapter supplies current at 24V that would mean that the current limit is 164w/24V = ~7A. Considering that the solar panels supply current at 18V, and assuming the same current limit of 7A that would set the maximum input power at 18V x 7A = 126W which is very close to what I measured. The net result is that one does not get the full advantage of the two 100w solar panels due to this current limitation which is disappointing.
The input power limit of ~126w led me to the next test measuring the total recharge time with a single 100w panel. I monitored the panel output hourly and used that opportunity to adjust the position of the panel to maximize its output, thereby keeping above 90w for most of the time. Since the days are shorter now and the sun is lower in the sky I had to run the test over two days to fully recharge the generator from 1% to 99% SOC. It took a total of 10.5hrs to recharge completely, which is a rate of 9.3% per hour and the rate was very steady all the way up until 99%. 9.3% of 1000w is 93w which is consistent with my observation of the fact that the output remained above 90w for most of the charging period. Also, 93w x 10.5hr = 977Wh which is also consistent with the fact that the SOC went from 1% to 99%, or 98% of 1000Wh = 980Wh. So, I suspect that during the typical star party season with the sun rising earlier and setting later than it does in Nov, one could fully recharge the 1000Wh generator with a single panel in one day.
Overall, I was suitably impressed with the build quality, design smarts and obvious capabilities of the Jackery Solar Saga 100. My truly on complaint is the price. At a price of $299.99 the Jackery 100w solar panels are more expensive than other folding panels. However, none of the other folding panels I have reviewed on line appear to have as durable, compact and ergonomic design as the Jackery. Nonetheless, it is best to keep an eye out for one of Jackery's sales to get the best possible price.
High efficiency solar cells
Lightweight with handles
Sturdy, durable design
Embedded USB charging ports
No protective case
Hard wired charging cable
You can shop for Jackery products at Amazon.com. Links are Amazon Associate links.
Edit: You can find a video version of my Jackery 1000 and 500 review on YouTube
I have been powering my astronomy rig in the field using either two 100Ah lead acid deep cycle batteries or my Yamaha EF2000is generator for a dozen years. While relatively cheap, batteries are heavy (50-60lbs), can only be discharged to 50% of capacity, are not voltage regulated, need to be maintained monthly, and do not have built in meters, USB charging, AC output, etc. At $1000 a generator is expensive, heavy (~50lbs), does not have either DC or USB outputs and is not permitted at most star parties. So I decided it was time to look at Li based power with solar recharging. Why Li? Because the power to weight ratio is much, much better than lead acid batteries, Li batteries have a higher depth of discharge (DoD) than lead acid batteries without damage and they maintain their voltage through most of the discharge cycle. The obvious downside to Li based power is the higher initial cost.
At first I considered 100Ahr LiFePO4 batteries like the well regarded Battleborn batteries marketed primarily to the RV and boating industries since I am planning to use these to add solar to my new RV in the coming year. But after much research I decided that a "solar generator" rather than a standalone Li battery is a much better match for astronomy applications. What is a solar generator? It is a Li battery with a battery management system (BMS), DC, AC and USB outputs, power input/output/SOC meter, an LCD display, power charging ports and a solar charge controller all built into a single lightweight, rugged and portable unit. There are many different suppliers of solar generators available today which are primarily marketed to the outdoor adventurer. Many solar generators use Lithium Nickel Manganese Cobalt Oxide (NMC) chemistry instead of LiFePO4
because of its nearly 2 to 1 advantage in energy density to weight ratio. I zeroed in on the solar generators from Jackery after reading many positive reviews about their design, features and performance. Their line of solar generators includes 160Whr (13.9Ah @ 12V), 240Whr (20Ah @ 12V), 300Whr(25Ah @ 12V), 500Whr (41.7Ah @ 12V) and 1000Whr(83.5Ah @ 12V) models with prices ranging from $139.99 to $999.99 with frequent sale pricing. These provide plenty of options for different astronomy needs. I contacted Jackery and suggested that amateur astronomers might be a market for them and they were kind enough one of their 1000Whr generators with a pair of their 100w solar panels for me to put to the test with my astronomy rig. Below are the results of more than a month of extensive testing in my backyard observatory and on a 3 night star gazing adventure in the field.
The Jackery comes well packaged with the generator shipped triple boxed. The PS1000 generator includes an AC charger in a soft carrying case, a car charger cable, an adapter to connect two solar panels in parallel for faster charging and a user manual. It enjoys free shipping, a 30 day free return and a 2 year warranty. Inside the box I found a registration card which enables a warranty extension to 3 years. The generator is solidly built using rigid ABS plastic casing and sports a smart functional design. With dimensions of 13.1 x 9.2 x 11.1 in. (L x W x D) it is only slightly larger than my lead acid batteries and fits nicely between the tripod legs of my mount. It's molded handle and weight of only 22lbs makes it a breeze to transport. Everything one needs to access is conveniently located on the front of the generator including:
1) a 10A DC cigarette adapter socket with dust cap;
2) a 5V 2.4A USB-A output ;
3) two 3A USB-C outputs;
4) a USB-A Quick Charge 3.0 output;
5) three 110V AC outputs from the internal 1000w pure sine wave inverter;
6) 8mm and Anderson Power Pole inputs to recharge the generator;
7) an LCD display which shows power output, input and battery % SOC and is low enough intensity as to not disturb fellow astronomers.
8) On/Off buttons for the power outputs and the display.
A small LED light is mounted on the side. The Jackery can be recharged with the included AC charger, with optional solar panels or by car.
I conducted a series of tests of the Jackery using my Software Bisque MyT mount, Celestron C11 OTA, Celestron focuser, ASI1600MC camera, Orion SSAG guide camera (not shown in the accompanying photo), Astrozap dew heat strap, TEMP-est cooling fans, and a Pegasus Power Box Advanced (PPBA). I used a cigarette adapter to 5.5mm x 2.1mm cable to supply power from the Jackery to the PPBA which in turn distributed power to the MyT, dew heater and focuser. The cameras and fans drew their power from the MyT. Since the MyT requires 48V I used a DC-DC up converter on the output of the PPBA to transform 12V to 48V rather than using the less efficient AC adapter. I use The Sky X (TSX) to control everything except the PPBA which is controlled by its own application. I did run one test using the Jackery's AC outlet to power the MyT without any problems but that method unnecessarily wastes power in the conversion process.
Since the first month of testing occurred during the massive wildfires here in CA I could not actually image. Instead, I ran everything exactly as I would during a regular imaging session with the ASI capturing dark frames to the laptop, the fans running, the guider taking dark frames and the heater powered at 50%. Since a laptop is typically the most power hungry device used and not everyone uses the same laptop, if they use one at all, I decided to run 3 different test setups:
1. Everything but the 15.4" laptop powered by the Jackery through the PPBA.
2. As in 1 but with the laptop powered through the Jackery's AC inverter.
3 As in 1 including a BeeLink mini-pc powered by the Jackery through the PPBA. The Beelink ran TSX and I used my laptop on its internal battery linked to the Beelink via Team Viewer as a monitor only to minimize power consumption.
For these tests I tried not to discharge the generator batteries below 20% SOC to be very conservative in terms of long term battery lifetime. The manufacturer specs the batteries to > 500 full discharges to 0% SOC so you could increase all of my total times below by 25% if you are comfortable using the full capacity of the Jackery. Here are the test results:
Test #1: I was able to achieve a total run time of 27hrs over 3 successive sessions before reaching a SOC of 20%. That is enough power for 3 nights of 9 hour imaging sessions without the need for a recharge in between, although a recharge is always possible. I noted that the ouput voltage of the Jackery remained steady at 12.9-13.1V all the way down to 20% SOC.
Test # 2: To extend the session as long as possible, I disconnected the laptop from the Jackery when it reached a SOC of 25% and let the laptop run on its own internal battery until it reached ~5% and the Jackery reached 20%. This powered everything for 9hrs, sufficient for a long overnight imaging session powering everything with the Jackery. Considering that the Jackery was able to be fully recharged with 2 solar panels in 7.5hr , one could run indefinitely this way so long as a reasonable degree of sunshine is available during the day. Alternatively, the Jackery could be recharged in 6-7hrs with an AC outlet.
Test#3: For this test I only used my laptop on its internal battery to check in on the BeeLink via Team Viewer occasionally. As I show below, the BeeLink which has no monitor consumes much less power than a 15.4" laptop so I was able to run for 8hrs and only draw the Jackery's SOC down to 59%. At that rate of power consumption I should be able to run for 15.6hrs without dropping the Jackery below a 20% SOC. That is nearly enough power for 2 nights of 8hr imaging without the need to recharge in between. Or I could use the extra power of the Jackery to keep my laptop powered using it as a monitor to check on imaging progress from time to time.
Actual Field Tests
While the tests at my home observatory are telling, there is nothing like an actual test in the field. So, just after the October new moon and with clear skies at last I headed to a dark sky site along the central CA coast. I did not use the SSAG since I wasn't guiding and I also did not need the heater. However, for all three nights I powered my laptop with the Jackery as in Test #2 above for a completely self contained test of the Jackery. The first night I powered everything up at 6:17PM, just before dark and rough aligned on the crescent moon. As it turns out, my first night would be one of frustration as I learned after running a 120 point TPoint model that my PA was way off. It took a second TPoint run for me to realize that my daytime mechanical alignment was so far off that I had to rotate the entire mount and tripod and adjust the gross altitude pin on the mount to have any hope of an accurate PA. After 2 more TPoint runs I finally got a good PA and was able to begin imaging the M74 galaxy in Pisces at f/10. I typically dislike first nights in the field given my history of such self-inflicted wounds. My frustration actually provided a good power test since the mount spent a great deal of the first 4 hrs slewing back and forth across the sky more than 500 times. I powered down at 2:15 for a total run time of 8hrs with the laptop still fully charged and the Jackery at a SOC of 28%. In other words, I could have run for another 2 hours if I had been able to stay awake. During the next day I fully recharged the Jackery with the solar panels in about 6hrs so it was ready for the following night.
I ran for 6hrs on the 2nd night completing my image collection of M74 and finishing with 50% SOC, easily recharging once again with the solar panels during the next day. The final night I ran for another 6 hrs finishing with 47% SOC as I imaged the edge on spiral galaxy NGC891 in Andromeda. Overall, the Jackery performed as I had expected allowing me to image for as long as 8-10hrs had I been able to stay awake, fully recharging each day with two 100w solar panels to be ready for the next evening. I was also able to use the Jackery during the day using its pass through charging feature to keep my cell phone recharged. Pass through charging allows the Jackery to simultaneously charge a device like the cell phone or laptop, while it is itself being recharged by solar or AC power. It will take correspondingly longer to recharge the generator depending upon the power used to recharge the connected device.
Power Use Case Analysis
Since everyone uses different equipment for their setups, I used the PPBA to measure the power requirements for each individual device and built the power consumption table shown below. Since my camera does not have cooling, I borrowed an ASI294MC Pro with cooing from a friend and measured the power requirements for three different degrees of cooling. Not surprisingly, the biggest power draw by far is my laptop and that is with the display turned down, Bluetooth and WiFi turned off. The camera cooler and dew heater on full are the next biggest power hogs. I find that I can usually run my heater at 50% with a dew shield and not have any dew problems, but others may find they need to run full power. Also, smaller OTAs will require smaller heater straps and correspondingly less power. The MyT mount power increases during slews but as I found when running TPoint in my field tests, 15w is a good average power consumption to estimate the total power needs for this mount if running by DC. In the past I measured the current requirements for a number of different mounts (CGE, CG5, Nexstar 6", ETX80 and IOptron Cube) and found that they use significantly less power than the MyT ranging from 2w to 6w during tracking. The ASI1600 is typical of cameras, including guiders, which operate on 0.5w or less without cooling. I do not have a powered filter wheel or camera rotator but I suspect that the power draw from those is negligible since they are used sparingly through the course of the night.
Taking these numbers into account, the following table summarizes the power required for each of my test cases and the corresponding maximum capable run time for discharges to 20% and 0% SOC of the Jackery. I added an additional case called "Hypothetical" which is identical to my Field test with the laptop powered by the Jackery up until the last 2 hours, but I added the additional power requirements of the dew heater at 50% power (10w) and a camera cooler at 100% power (20.5w) to get a total power requirement of 112w. One can see that for a setup that draws between 40 and 60w, fairly typical of an imaging rig using a mini-pc or a separately powered laptop, the Jackery 1000 can supply multiple nights of power without a need to recharge in between. Even in the most power hungry 'Hypothetical" case the Jackery 1000 can supply power for a long night of imaging.
As noted above, the Jackery has a regulated power output. In my tests, the output voltage remained between 12.9 and 13.1V all the way down to 15% SOC showing excellent power stability. Another thing to note is that the drop in SOC was very linear with time, falling by the same % each hour all the way down to 15%.
Like all other solar generators that I have investigated, Jackery specs the battery life to >500 full cycles after which the full capacity of the batteries will drop to 80%, or 800Wh for this particular model. At that point it will still supply 80% of its original capacity so one would still be able to get continued use out of it but the total run time would be shorter than during the first ~500 or more cycles.
The Jackery can be used to power devices over the temperature range of 14deg F to 104deg F which will cover the typical star party season but might be a problem for hardy soles who like to observe away from home during frigid nights. Recharging of the Jackery requires a temperature above freezing, 32deg F, but I read of a clever trick where the generator is placed inside a cooler so that it stays warm enough under its own heat while recharging at temperatures below 32deg F. These are limitations typical of Li-chemistry batteries and it should be noted that the BMS will prevent the battery from being used outside these conditions so it cannot be accidentally damaged. Maintenance of the generator is simple requiring a discharge to 50% SOC and recharge once every 3 months.
I am thoroughly impressed with the build quality, performance and ease of use of the Jackery PS1000 as a source to power a typical astro-imaging session through a long night under dark skies. With the option to recharge within 7hrs by AC outlet and 8hrs by twin solar panels, if not less, I can look forward to eliminating those heavy lead acid batteries and avoid annoying my friends with my generator running through the night. The biggest downside to the PS1000 is its price. However, when I look at the cost of two 75Ah AGM batteries needed to match the Jackery's power, plus a quality pure sine wave inverter, MPPT charge controller for solar charging, power meters, USB charging sockets, cases, etc. I believe the cost of a DIY system easily exceeds $600 not counting the assembly effort. And one still has to carry two 50lb home built power supplies and connect them in series. Another consideration is that the Jackery can double as a backup generator in case of a power outage. The PS1000 will keep my refrigerator running for 9hrs before needing a recharge and, unlike my Yamaha generator, I can use it inside my house. For those with lesser power needs, say 40-60w the $499.99 Jackery 500 would be a lower cost option to achieve a 7-8hr imaging session. And for visual observers, the much less expensive 160 and 240w models would be more than sufficient for their power needs.
I gave the folks at Jackery feedback on how they might make their generators more user friendly to the astronomy community. First, they might consider a 5.5mm x 2.1mm or an Anderson Power Pole DC output in addition to the cigarette adapter output. Or they could supply a cigarette adapter to 5.5mm x 2.1mm or Anderson Power Pole extension cable to make it easier to for us to connect the Jackery to our equipment. However, it was easy to find a cigarette to 5.5mm x 2.1mm power cord on Amazon that serves the purpose.
The Jackery generator can be recharged with one or two of the Jackery Solar Saga panels in parallel or, with an MPPT to 8mm adapter with any solar panel under 30V and 10A. I plan to do a separate review of their solar panels in another blog soon so look for that soon.
High capacity and DoD
Extremely light weight
Well designed and simple to use
Simple to add solar recharging
Single 12V output
No 5.5mm x 2.1mm or Anderson Power Pole output
500 cycles to 80% remaining capacity
You can find more on solar generators on my YouTube Channel.
If you want to find out more about and shop for Jackery products, you can find them here Amazon.com. Links are Amazon Associate links.
Never Over-Tighten Your Hyperstar
I used the Hyperstar almost exclusively on my C14" Edge telescope with great success for years. Then one time I found that the Hyperstar would not unscrew from the secondary holder. No matter what I tried the Hyperstar was firmly attached to the secondary holder threads and would not come off. In fact, the more I tried to entice the Hyperstar loose I only succeeded in making the secondary holder spin in the corrector plate. Oh boy! What now? I reached out to Dean at Starizona who was a great help in solving my problem. He explained that the gasket that Celestron uses between the inside of the corrector plate and the secondary holder does not have sufficient grip and slips if the Hyperstar is tightened too much, as it was in my case. The solution, remove the corrector plate to get access to the backside of the secondary holder to release the Hyperstar. Once done, just replace the original gasket with a stickier one from Starizona and re-assemble. Well I did that but apparently I did not get the corrector plate centered on the primary mirror as well as I should have. How did I know that? Just look at this image I took of M33 and you will see that the stars in the corners are elongated in the direction of center indicating a collimation problem. Adjusting the secondary using the three screws was not sufficient to improve the collimation since the problem was that the secondary was no longer centered on the primary mirror. I read on CN about a technique using the circular rings formed by the primary mirror, baffle tube, secondary mirror and corrector when you look down the center of the optical tube as a guide to getting the corrector plate centered. The objective is to adjust the corrector plate using the screws on the outside of the optical tube (for Edge only scopes) until the ring of the corrector plate is centered. I tried this but found it too difficult to maintain a steady enough line of sight down the center of the tube to be certain how much I needed to adjust the corrector. I even tried setting up my iPad on a tripod to photograph the set of rings as shown in a YouTube video. But even this was not very successful for me. Apparently, this method does work for many people, but it wasn't going to work for me.
The moral of the story ... snug is good enough for the Hyperstar!
The HoTech Laser Collimator to the Rescue ... Not Quite Yet
That led me to purchase a used HoTech Advanced CT Collimator on Cloudy Nights. The HoTech kit consists of a collimator plate, a Reflector Mirror with removable cap and a tripod adapter. There are four lasers on the back side of the collimator plate, one in the center and 3 at 120 degrees apart at a radius of several inches from the center. The laser in the center provides a cross-hair pattern for alignment of the plate to the telescope primary mirror. The 3 other laser provide parallel beams of light to simulate a distant star. The collimator plate has concentric alignment rings on its face for accurate collimation of the scope. The tripod adapter is used to attach the collimator plate to your own tripod and provides tilt of the collimator plate in two axes. The Reflector Mirror is inserted into the visual back or focuser to reflect the laser beams back to the collimator. If using the HoTech to collimate an SCT without Hyperstar this is all that is needed. When collimating with Hyperstar the optional Hyperstar upgrade kit is required as discussed below.
Before attempting to use the CT Collimator I read a CN thread which indicated it was a good idea to check that the lasers on the collimator were themselves collimated before attempting to collimate the SCT. The thread provided a convenient method to do that using a paper target with a cross hair, a circle and 3 spots 120 degress apart where the lasers are positioned on the HoTech Collimator. The procedure is described here and works quite well.
Using this method I came to the conclusion that one of my lasers was slightly off collimation. In principal, having found the offending laser I could adjust the laser myself to get it back in collimation. However, I was concerned that it was more likely that I might make it worse so I decided to send the collimator back to HoTech for adjustment. My only cost for the service was the postage. When I got the collimator back I set it up in my garage with the same paper target and verified that all three lasers were lined up where they should be.
While waiting for my collimator to be aligned at HoTech I came up with another method to check the laser alignment using a small mirror instead of the paper target. Lining up the HoTech collimator 15 feet from the mirror and square to it enables the 3 laser spots to reflect off the mirror back onto the collimator. If the reflected laser spots all reflect back onto the lasers on the collimator, everything is in alignment. The advantage of this method is that the distance is effectively doubled providing greater precision.
If you buy the HoTech Advanced CT collimator new you should not have this issue, but it is probably a good idea to check either using the paper target on the wall or the reflection from a good mirror. The originator of this CN blog insisted that I should not use a mirror as imperfections in the mirror would throw off the lasers. I understand that argument but if the reflected laser spots return to their origins as they obviously do in the image below after David at HoTech re-collimated the lasers, imperfections will not cause out of alignment lasers to appear in alignment.
Mastering the HoTech Advanced CT Collimator
Having certified that my collimator was in collimation I proceeded to the task at hand, to collimate my 14" SCT. Anyone who has used one of these will tell you that the initial step in the process is the most time consuming, tedious and most confusing step. And it is the most important step to get right. Once you get this done correctly, the rest is easy. Conceptually the first step is simple. Get the CT collimator plate in the same plane and on axis with the primary mirror. That is done by first attaching the HyperStar Reflector Mirror Assembly to the Hyperstar. The Assembly consists of an adapter ring, Reflector Mirror and a target cap. Next attach the collimator to a tripod with the included holder. The holder provides tilt adjustments along two axes which will be used to help align the collimator to the primary mirror.
The following steps are performed with the collimator switched to Mode 1 using the center laser only to shine a cross hair pattern onto the telescope. Upon reflection from the primary mirror, this produces a clipped cross hair pattern on the collimator plate as seen in the image above. Next, adjust the height and distance of the collimator relative to the scope so that the cross hairs are centered and symmetric to one of the rings on the collimator. It is not necessary that the tips of the cross-hairs fall exactly onto one of the rings on the collimation plate, only that they be symmetric to the center of the plate. If the room is dark enough, you can also see a diffuse doughnut of red light from the laser collimator. Either the doughnut or the cross hairs can be used to do the alignment. Once either the cross hair or the doughnut is aligned, both will be aligned. I should note, that you will also move the telescope up and down or left and right to help align the collimator to the primary mirror. As the instructions say, repeat this process one or two more times but with smaller adjustments to get the alignment as spot on as possible. Also, it is best to set the collimator as far away from the front of the telescope as possible for higher precision. Typically it should be outside the Back Focal Length which is the point where the cross-hairs converge to a spot in the center of the collimator.
You will notice that the inner edges of the cross hair (and doughnut) are clipped. This is due to the shadowing of the Hyperstar (or secondary). Likewise the outer edges of the cross hairs define the outer edges of the primary mirror.
I should note that it is much better to do this process with the scope pointed upward, say 45 degrees, as it would be while observing. The weight of the mirror will cause a slight shift in position inside the optical tube when elevated which will change the collimation slightly if this procedure is done with the telescope pointing horizontally. I did this and found that unless you have a very tall tripod or a 8" and smaller SCT you will have to put the tripod on a table and tilt the collimator to the same angle as the scope. When set up like this, the process is even more confusing in terms of moving the tripod around to get co-planar alignment of the collimator and the mirror. But, eventually I succeeded. Having aligned the collimator plate to the primary mirror the hard part is done. You may have to re-check that you have not disturbed this alignment in later steps and re-adjust if needed.
The next step is to make sure that the Hyperstar (or secondary if not using the Hyperstar) is centered on the primary mirror. Switch to Mode 2 which turns on the three lasers at 120 degree angles around the collimator plate. This creates three laser spots on the Reflector mirror target cap. Adjust the telescope focuser until all three dots converge into a single dot. If three spots are not all visible on the Reflector mirror target cap you will have to go back one step to realign the collimator to the primary mirror. Next, remove the Reflector mirror cap to allow a second smaller cross hair pattern to reflect from the Reflector mirror onto the corrector plate. This cross hair shows the tilt angle of the Hyperstar focal plane to the primary mirror. Adjust the push-pull pins on the Hyperstar to center this cross hair on the corrector plate.
The last step is to center the Hyperstar on the optical axis of the primary optical axis. Put the Reflector mirror cap back onto the Reflector mirror. The three laser spots should still be converged into a single spot. Next, this spot needs to be centered on the Reflector mirror cap. This is done on an Edge by loosening the screws on the front of the optical tube which hold the corrector retaining ring in place and then making use of the 3 adjustment screws on the outside of the optical tube to center the inner edges of the cross hairs on the same circle. If you do not have an Edge, you have to adjust the corrector manually until the secondary is properly centered.
This completes the collimation process with the HoTech Advanced CT Collimator. The final step is to do a star test on a night with good seeing. Minor adjustments of the Hyperstar push-pull pins may be necessary to fine tune the collimation using the standard procedure for star collimation.
When not using the Hyperstar, the process to align and center the secondary is different but is detailed in the HoTech Collimation manual and YouTube video which can be found in the links listed below. Also, when not using the Hyperstar, there is the added step of aligning the focuser to the optical axis. This procedure requires that the Reflecting Mirror supplied with the collimator be installed in the focuser and the secondary mirror removed so that a second cross hair pattern reflected by the Reflecting Mirror appears on the collimator screen. When this cross hair is centered on the collimator plate by adjusting the appropriate screws on the focuser, the optical alignment is complete. .
The final proof of good collimation was obtained by taking an image with the Hyperstar of a galaxy with lots of stars visible out to the edges of the field of view. Since much time had passed since I had imaged M33 to discover my collimation problem, it was no longer visible. So M101 was chosen as the test target since the FOV of the image has plenty of stars out to the edge to check for coma. As you can see in the image below, the stars are much improved at the four corners indicating much better collimation.
While the HoTech Advanced CT Collimator is both expensive and requires a steep learning curve, it works extremely well allowing collimation during the day time or on a cloudy night. Unlike a star test, it also provides the ability to check the centering of the Hyperstar (secondary) and the alignment of the focuser to the optical axis of the primary, both of which can cause problems with star shapes when they are out of alignment.
If you choose to use the CT Collimator, remember to be patient the first time you do it and use the helpful documentation in the links below. Good luck!
If you are interested in the HoTech CT Collimator you can find it here. Make sure you get the right :
HoTech CT Laser Collimator - 2" collimator with accessories
HoTech CT Laser Collimator - 1.25" collimator with accessories
1.25" Reflector Mirror - separate mirror for a 1.25" opening
2" Reflector Mirror - separate mirror for a 2" opening
OPT links are Affiliate links.
HoTech has made a very helpful video which shows each step of the collimation process but with the secondary mirror in place, not the Hyperstar. It can be found here: www.youtube.com/watch?v=4BDwa0RVZw0
The complete written collimation instructions with illustrations, for both the Hyperstar and non-Hyperstar setups can be found on the "Helpful Links" page of this web site.
There is also a CN thread showing a clever homemade jig to help make the collimation process easier which can be found here:
The introduction by ZWO of their camera, the ASI1600, in early 2016 has been a game changer for Camera Assisted Viewing (CAV), also known as Electronically Assisted Astronomy (EAA) or Near Real Time Viewing. This camera was the first astronomy camera to use Panasonic's latest CMOS sensor, the MN34230. The 4/3 format sensor has 16.3 Megapixels (4644 x 3506), each 3.8 microns square with a total chip size of 17.6 x 13.3mm. The larger chip size has a diagonal of 22mm which provides a much larger field of view compared to the cameras commonly used for CAV . Compare this to the analog cameras from Mallincam which have less than 0.5 Megapixels and diagonals of only 6 and 8mm depending upon the camera model. Even the recent CMOS cameras like the ASI224 only has 1.2 Megapixels and a diagonal of 6mm, much smaller than the ASI1600.
And with 3.8 x 3.8 micron pixels it provides high resolution images for excellent image detail. Additionally, this sensor supports extremely low read-out noise on the order of 1 electron which made stacking many very short exposures much more practical. This reduces the demand on the quality of the polar alignment and the mount tracking for a successful CAV session. With such a large sensor and 16 million pixels, this chip supports binning 1x1, 2x2, 3x3 and 4x4 which trades resolution for sensitivity by making the "effective" pixel size larger. This is also useful in tailoring the image scale (arc-sec/pixel) to different optical setups.
Panasonic's new sensor was quickly incorporated into new cameras from ZWO, QHY, Mallincam and others and soon took the CAV community by storm making these the new hot cameras to have. ZWO was the first to incorporate this sensor into its ASI1600 camera which came in both uncooled Color ($699) and Monochrome ($899) versions. The uncooled color camera is now discontinued, but still can be obtained on the used market. They later came out with a cooled Monochrome version ($1280) called the Pro with 2 stage cooling down to -40deg, a 256MB DDR3 memory buffer to help avoid lost frames during high rate data transfers, a USB3.0 port and a USB2.0 Hub to connect accessories such as a filter wheel, guider and a focuser. The camera also has an autoguider port in case you want to use it as a guide camera.
QHY and Mallincam soon followed with similar cameras of their own incorporating this new Panasonic sensor. The QHY163 comes in color ($899) and monochrome ($1199) versions and also includes 128MB of DDR memory, a USB 3.0 interface, guide port, two stage cooling to -40C cooling and a sealed chamber with a heated window to prevent dew from building up. Mallincam's SkyRaider DS16 comes in 3 versions, color ($999), monochrome ($1299), both with a fan for passive cooling and TEC version ($1700 color, $1900 monochrome) with active cooling. They all have a USB 3 interface, a sealed chamber, DDR memory and a full featured software, Mallincamsky, for camera control, capture, live stacking and dark frame subtraction. The TEC version includes a USB Hub and a heated window for dew prevention. Both the ZWO and QHY cameras use the free software Sharpcap which performs all of the same functions as Mallincamsky and much more if you pay for the Pro version, but that is a topic for another blog.
There are still more versions of cameras incorporating the Panasonic 4/3 chip, but I will not list all of them here.
These new cameras appear to have had two major impacts on the way we do real time viewing.
First, if you read the threads on the Cloudy Nights forum, you will see that many amateur astronomers have moved away from the long exposures of 30 sec to minutes common with the security type astronomy cameras like the Mallincam Xtreme and Xterminator or the Revolution Imagers 1 and 2. With such low read-noise it is now practical to use programs like Sharpcap to stack many very short exposures of a few seconds on the fly to get as good or better image after 30sec to minutes but with less demand on the quality of the mount and the polar alignment. In fact, Alt-Az mounts become even more practical for CAV with such short exposures and the use of an on-the-fly stacking program. This can both minimize the cost of the setup and reduce the overall hassle in getting a good polar alignment. Obviously, a better mount and more time spent on a good polar alignment will improve the experience, but less so with exposures of 2 to 5 sec which is now practical with this new sensor.
Second, since the pixels are square not rectangular stars are round unlike their appearance with CCD analog cameras and they do not have the black halo common to stars in images taken with analog cameras. Also, with pixels about 1/3 the size of the pixels in analog cameras much more detail can be seen in galaxies and nebular with the new sensor. Images obtained are of much higher quality than ever before. The net result appears to be a move by many CAV folks more and more in the direction of traditional astrophotography. It has become increasingly the case that dark frame subtraction and even flat frames are both employed with on-the-fly stacking to get the best possible image. The ideal case is to be able to view the image in real time to get the immediate enjoyment of observing deep sky objects, while saving individual frames for later post processing to obtain an astrophotography quality image. In fact this can be done with Sharpcap using the Live Stacking feature while selecting the option to save individual frames in FITs or PNG format for later post processing.
As is always the case, time marches on and even newer products come to market. It appears that the successor to the ASI1600 is the ASI294 with the Sony IMX294 CMOS chip. It too is a 4/3 sensor with extremely low read noise. Even thought it has less pixels at 11.7 Megapixels, the major new advantage of the ASI294 is it's much deeper well which provides a significant advantage for dynamic range. Perhaps a topic for a later blog.
I have been using the ASI1600MC for the last two years and am very happy with it. However, only the mono versions are still available. My astro buddy uses the ASI294MC color cooled version and has had great success with it.
You can find the products listed in this blog in the links provided below. As an OPT Affiliate I can earn from qualifying purchases through my site with no additional cost to you. This helps to defray the cost of this website.
ZWO ASI1600MM Uncooled - this is the mono version of the camera I have
ZWO ASI1600MM Pro - cooled mono version of the camera I have
QHY163 - QHY's cooled version of the color camera I have
ZWO ASI294MC Uncooled - this camera is one of the most used cameras for EAA
ZWO ASI294MC Pro - this is the cooled version of the 294
Revolution Imager II - analog camera which I have used and reviewed elsewhere
Many people who do video astronomy like the option of keeping things as simple as possible. This is one reason to choose an analog video camera at a time when many are moving to digital video cameras like those from ZWO. The analog cameras do not require a computer unlike the digital cameras. An analog camera only needs a video display device which will accept an analog input. A light weight 7" or 9" LCD will suffice for viewing by 2-3 people. Simply connect a video cable between the camera and the display to view images. The camera can be controlled with the 5 control buttons on its back, or with a hand control if the camera is configured for one.
But what if you want to ditch the video cable and LCD monitor to further simplify the setup? That is quite easily done with a WiFi Emitter and your phone or tablet making the gear requirements including power all that much simpler.
The WiFi Emitter connects to the camera analog video output and is compact and lightweight enough to be attached to the telescope with the accompanying double sided adhesive. It can be powered with the same 12VDC battery used to power the camera further minimizing the number of required cables. If both the WiFi Emitter and battery are attached to the telescope there will be no need for long cables nor any concern about cord wrap or snags on the mount, etc. The WiFi Emitter works with Android and Apple devices, both phones and tablets and is very simple to setup and connect. With this you can view your video images on your cell phone or tablet completely untethered by cables over distances of 150ft or more depending upon intervening obstacles. I was able to connect to my camera in the back yard from inside my house. If you also have WiFi control for the telescope mount, say through Sky Safari or similar, this setup makes for a very comfortable viewing from inside your home.
You can get a WiFi Emitter from Orange County Telescopes (OCT), the home of the Revolution Imager 1 and 2, for $90. If you are more of a DIY person you can obtain one on Amazon for less than $40 if you search for"AV WiFi Emitter". The WiFi emitter comes with 3 short cables hard wired to the unit, a screw on antenna and an instruction book. The one I bought from Amazon also came with double sided tape which I used to attach the emitter to my camera but you could also attach the emitter to your scope instead. It also included plastic cable ties and another power connector in case I wanted to hard wire the power input to a power source. The emitter sold by OCT does not have the tape, cable ties nor the extra power connector but does include an RCA to BNC adapter which is needed to connect the emitter to the camera. If the emitter you purchase does not have this adapter, you can purchase one on Amazon for a couple of dollars.
The emitter has three short cables. The yellow cable connects to the video output of your camera. This cable has a male RCA jack so you will need an RCA to BNC adapter to make this connection. The other two cables are red and are for the power connections from the battery and to the video camera. Connect the power from your battery to the red input connector which has a female DC plug and connect the other red cable with a male DC plug to the power input of your camera. The WiFi unit runs on 9 -30V DC so a simple 12V battery used to power your analog camera will suffice to power it as well.
A one time setup of the required software is necessary to get started. Using you phone or tablet connect to your APP store, simply search "WIFIAV" software and install it. For iPhones and tablets this would be the Apple Store and for Android phones and tablets this would be the Google Play Store. You will see an icon on your phone that looks like the emitter broadcasting a signal from the antenna. This is the app you will need to launch whenever you want to connect wirelessly to the camera.
When you are ready to connect to your camera, turn on the power to your emitter and camera and you should see the Red LED on the emitter light up. Next, push the button on the emitter and you should see the green "Link" LED on your emitter light up. Now go into your phone or tablet settings and connect its WiFi to "WIFIAV". You may need to type in a password the first time you connect which is probably "12345678", and will be included with the instructions which came with the emitter. Launch the WIFIAV app on your phone or tablet and you will see a screen with 6 blue icons at the bottom and an image from your camera if you are already pointed to an object and focused. Or, you may see the camera menu screen if you have enabled that. Shown here is the camera menu for the Revolution Imager 2. At the bottom of the screen are 6 WiFi controls to capture a video, record to a DVD, save an image, check the emitter signal, go to a file folder which contains the saved images and videos, and change settings. If you plan to only view images live you need not use any of these. If you would like to save images to your phone or tablet just click on the camera icon. You can retrieve these using the file folder icon.
You are now ready to view images from your camera remotely. Just move your telescope to the object of interest and adjust the camera settings as you normally would and you are ready to view objects from planets to DSOs wirelessly on your phone or tablet. While this device makes wireless viewing a simple reality, I have to say that the image quality is definitely not as good as what I can see with the video hard wired to an LCD. I believe there is some video compression which occurs in the wifi transmitter which causes this. Nonetheless, this device enables one to step away from the telescope, view effortlessly from inside or walk around at a public outreach event and share images live without having to crowd around the telescope.
You can find the WiFI discussed in this blog and which I use in the link provided below. As an Amazon Associate I can earn from qualifying purchases through my site with no additional cost to you. This helps to defray the cost of this website.