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Apr 26

Deep discharged battery


I didn’t have my charger connected but I connected the shutter motor power while I was installing the track. Of course I left it connected and now the battery is dead.


Babak gave me the part number to buy a new battery but I was wondering if anybody had any luck recovering a dead battery with a beefier charger or something.


I know I’m Cheap but before I go spend $50 I’d like to know. Also I figure in case I have a shutter close due to bad weather and the dome doesn’t park, won’t I have the same problem?

Go to I got a spare 9Ah exact same size for less than $50. I also replaced the charger with a LeicesterCN at amazom. Has more ommph but still safe to leave on battery 24/7.


Also! I killed my battery just like you did once. It will recharge just fine if you have a bigger charger. I just connected my other big charger and set it for a 2A rate and all was well. You may lose a few discharge/charge cycles because of it getting killed but should work OK.

Good luck!




There is a repair mode that can repair and recharge even deeply discharged batteries. It worked for me...

The dome park thing to get onto tabs is a great thing about ACP. THere you have what is called a weather script which does whatever you wish. Mine starts dome homing and then starts shutter closing; finally, mount is parked. Basically if the dome was at 180 (home is at 0) it arrives there about 4 sec before shutter is fully closed.



Thanks guys. I have a better charger and I hope to recover this one. If not I’ll try walmart.


Also, I thought something like this might exist but would there be anything stupid about connecting a little switch in line with the battery that prevents it from discharging below 10V? I‘m Looking online and they are like $10. Surely that’s worth it unless it would prevent the shutter from closing if needed.

Hello Again! i just looked at several battery cutoff modules at amazon. Very neat items!! In the $10 - $15 range. They seem to draw about 100mA. Now the arduino by itself is about 50mA. Figure about 1/2 of battery capacity used per cycle for long life (lead acid.) My 9Ah would last about 100 hours with arduino alone or 33 hours with the protect module - at best. I'd rather personally keep the power for the shutter. For me I just remote in with VNC and look at shutter voltage in driver setup (use POTH for that). A couple of minutes after it hits the tabs I see ~14V showing it's charging. Once charged it goes back to ~13.1V. If I see something like 12.7V it means the shutter missed the tabs. This happens about once out of 50 times. Just rotate to 350 then re-home. Done.

The key thing is when shutter closes have it land on tabs. All will be well then. Humm.. that $10 circuit might be a op amp as comparitor running a relay?? I could use one.. Also!! I set my "low battery" value in driver as 10.2V because when it is moving it can sag a bit. Indeed 10.0 is totally dead for a 12V - ya do not really want to go there unless by accident.


Good luck!! Ron

I tested the voltage with my voltmeter and it was 10.1. So I just connected up a heavier duty smart charger that cycles the amps to get the best recharge. It happily hummed along and accepted the battery as chargeable (it tests for dead cell, short, etc before starting). So I think this was an easy fix. Maybe the protector circuit isn’t necessary. Certainly don’t have to buy a new battery.

@Ron Crouch you know... it’s the principle of the thing. Had it for literally a day and it’s unusable. I didnt think about disconnecting it during the install process where you need to feed the track in. even then you would figure the battery tender would be able to kick on anything about 10 volts.

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