External Power Sources for S50

Gordon

I apologize if this question has been asked before. I have a question about external power sources. I only use the Seestar S50 on my deck so I have easy access to an AC outlet. Will AC power keep the S50 running indefinitely? If not, what is the simplest solution to extend battery life on the S50? Thanks. Gordon

Support@Seestar

Gordon
In theory, it is possible, but it will lose the battery life, perhaps only 5 minutes of the last two hours of charge, in this case, or directly replace the battery.
So it's not recommended.

starnet59

The S50 will run indefinitely with an external power supply, although I do not see why you would need more than 12 consecutive hours? How long are the nights at your location ;-)

There will be some impact on the battery life if you keep it charged at 100% all the time. On the other hand, I have been using my S50 in this mode for over a year and I have not seen any battery degradation, and I do not care if that happens since I am always using it externally powered.

wvreeven

Actually, it may not operate forever depending on the USB adapter used. If it doesn't provide enough power and the SeeStar consumes more, the internal battery will be used as well, which may drain if too much time passes. See the discussion at https://bbs.zwoastro.com/d/21947-powerbank-use/

yDrqQBnb

I think the main problem when using external power during a long time is the cable... except if the seestar never move on itself...
it's better to use a powerbank fixed on the seestar.

Gordon

Would this work as an external power source for the S50? I already have this to charge my iPhone.

curtismacc

Assuming that the external supply has sufficient current and power capability the only reason I know that the Seestar will stop working is when the internal battery fails. A supply with 3A and 15W should be more than sufficient since the Seestar only draws _4W while tracking and imaging with bursts up to 7-8W when slewing to a new target or closing the arm. Do the math, the internal battery is rated at 22.2Wh but in tests it takes about 26Wh to fully charge from 0% SOC to 100% SOC (may be slight variations from battery to battery). Hence the 6 hour estimated run time (26Wh/4W =6.5hrs). Add another 0.5W for the dew heater. Also if you do a fast slew I have measured 10-11W so 15W should be more than enough external power to avoid tapping into power from the internal battery.

Now, it is true that lithium ion batteries do not like to remain at either 100% or 0% SOC. In the former case that puts stress on the anode and in the latter stress on the cathode. This can cause cracking and delamination which ultimately leads to loss of lithium capacity (LLC) as it is termed in the technical literature. But, as Seestar Support says it will be small and will take a long time to degrade the battery significantly. The internal battery can be replaced very easily and I see that Agena Astro finally has the replacement batteries available. You could avoid degrading the internal battery life by discharging it to ₆₀% SOC in between sessions and then charge it back up to 100% SOC before your nightly session with the external source if that is possible but I think it may not be worth the trouble.. When using an external AC-USB source to power the Seestar with the internal battery fully charged before your session you can now operated below the -10C discharge spec for the internal battery without worry since the internal battery won't discharge. Now, you may still have to worry about other internal components at too low of temperatures but that is a different matter.

Best Regards,
Curtis

Gordon

curtismacc
It seems like I don’t get much more than 4 hours of internal battery life in this cold weather & the dew heater on. Curtis. Are you saying that I can safely use an AC -USB C adapter for unlimited imaging time? No external power pack is necessary? Thank you Gordon

curtismacc

Gordon 4 hours with the dew heater in cold weather (it would be nice if you quantified what you mean by cold weather) sounds reasonable. All battery types, lithium ion included, loose some capacity in cold temperatures. After all, the key to how batteries work are the chemical reactions which take place inside and these need thermal energy to proceed. Fortunately, lithium ion batteries do much better in cold temps than most other battery chemistries.
Yes, if you have access to AC you can use that to continuously supply power to the Seestar to keep it running all the time. You just need to make sure that the AC-USB power adapter supplies enough power and current to keep the Seestar happy. Then you can run continuously as the internal battery just sits there remaining fully charged. Obviously you would need a power bank or portable power station or battery with a USB converter if you don't have access to AC

Best Regards,
Curtis

jdaley

Gordon - If plug-in works for you, do it. I have to assume you don't leave your S50 out in snow or rain. Lithium batteries degrade faster, we are told, faster if not cycled. How much faster? I personally have not seen a number. I use mine on my deck as well and initially ran the cord and plugged in. I tripped on the wire one night then transitioned to the powerbank. The powerbank you showed appears to be similar to the 145W ugreen I have. If and when the internal battery does crap out, a replacement is sold at Agena Astro. Maybe the S70 will be available by then.

curtismacc

jdaley

jdaley Lithium batteries degrade faster, we are told, faster if not cycled.

Lithium ion batteries do not have memory like NiCd or some other battery chemistries. You don't need to fully discharge nor fully charge them to avoid losing capacity. But, most manufacturers recommend fully charging a lithium ion battery so that the internal BMS balances the cells from time to time. It will only do this when the cells are charged to their maximum voltage. Not sure if the Seestar internal BMS equivalent does this but I suspect it does.
It is true that lithium ion batteries do not like to be stored at either 0% SOC or 100% SOC as I explained above.

Regards,
Curtis

Gordon

This post I made here was one that 1 posted on a similar thread:
“Last night I used the Seestar S50 for 10 straight hours using the same external power source that I use to recharge an iPhone. Both the Seestar battery & the external battery were at 100% at the beginning of the night. At the end of the night the S50 indicated 100% Seestar battery life while the external battery was 27%.”

Gordon

curtismacc
When I say cold weather, I’m talking about winter temperatures in Pittsburgh, Pennsylvania. I understand that you grew up in Pittsburgh, so you are familiar with winters here.😉

curtismacc

Gordon Cold, but not Minn. or Canada cold. So, yes you will see some loss in capacity but I have not experience with those temps any longer since I live in CA now. Nonetheless, your experience makes sense as I said above.