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LiPo Battery Question

Cain Seldon

Junior Member
#1
Hey guys, this is my first post on the forums. I've been following FliteTest on youtube for about two years now :) I intend to get into multi-rotors with the ultimate goal of flying camera drones for personal and potentially paid work. But till then…

I have a Dromida Kodo, and have been practicing indoors. I've been flying it for about a week, with its fair share of crashes as I get used to the concept of multi-rotor flight (I'm used to airplanes). However a few nights ago the throttle got stuck and it smashed into a wall fairly hard and fell behind something. I wasn't able to retrieve it till a few days after. There wasn't any visible damage, but the lipo battery does not charge anymore (LED on supplied USB charger flashes once then turns off, doesn't matter if plugged into a USB port or an outlet). Obviously because I didn't retrieve it for a few days the quad was on till the battery died.
My question is, do you guys think the battery over-discharged due to the quad being on for a few nights? And are there any fixes or do I need to get a new battery? (I have a spare I ordered last week on its way).

If you guys need anymore information just ask!

Thanks,
-Cain
 
#2
yeah, it sounds like you over discharged it. I've done it with bigger batteries. kinda a bummer cause its now junk, but you can recycle it at a batteries plus, or your local hobby store might take it.
 
#3
Do you have a charger that can charge different battery types, cell counts, and selectable amperage? If so you can bring it back to life by charging it on the nimh setting at 1 amp. Once you see the voltage reach 3.3 then stop the charge. Plug it into your USB charger, or charge it on the lipo setting until it's full.

I've used this method on a couple of larger lipos and I still use some of them today. Be VERY careful when using this method. Sit by the charger and monitor the heat of the battery and its voltage constantly.
 

Cain Seldon

Junior Member
#4
Nah unfortunately I do not, since I'm just getting into the hobby. All I have is what came with the Kodo.

If it is over discharged, would it be worth saving the battery till I can get something that can do what you said? Or does waiting only exaserbate the issue?

As I am finishing up college (graduating in a few weeks) I don't have a ton of funds to buy a lot of equipment yet, so my budget is fairly low for anything. But in the meantime I can just buy a few batteries, they are only about 8 bucks each. I already bought one as well as some spare props and prop guards.
 

jhitesma

Some guy in the desert
Mentor
#6
If you're on a tight budget I'd suggest putting your money towards a new battery rather than trying to revive one that's been over discharged. You may be able to revive it...but...it's risky (like fire and smoke and caustic toxic smoke risky) and even if it works the pack won't perform as well as it did before.

Looks like that quad just uses standard 1s cells (370mah stock) which are fairly easy to find and cheap. You could even get some larger (600mah) packs that might give slightly longer flights (though their extra weight may negate the extra capacity) or try a smaller lighter pack and give up some flight time but possibly gain some performance from the lower weight.

The catch is...most replacement cells don't have built in protection circuits so charging them with the USB cord is risky since usually those USB cords don't have cut off circuits in them and rely on the pack having the protection circuit.

So my advice would be to save up a bit of cash (graduating college...maybe some graduation gifts coming ;) ) and pickup a decent charger and a handful of replacement cells.

If you do try to revive you original pack just be SUPER careful. When I've done that I did it outside, on a concrete table, with no combustibles around, and with the pack in an old broken microwave just in case. It worked, but the pack never performed well afterwards.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#7
yeah, it sounds like you over discharged it. I've done it with bigger batteries. kinda a bummer cause its now junk, but you can recycle it at a batteries plus, or your local hobby store might take it.
I just called my local Batteries plus and they confirmed this. They will accept and recycle for free any of the 3S or 4S lipos I am using damaged or not so long as they are not hot.

The hobby club we are just starting is still talking about salt water baths. :( I have been looking for a better alternative and I think this is it. Thank you Samick. This is HUGE. :)
 

Cain Seldon

Junior Member
#8
Well considering 'outside' for me is the streets of Manhattan, I don't think that is an option for me ;) But you are right, I think i'll just buy a few of those batteries and maintain them well.

However I do think ExperimentalRC has a point. I should pick up one of those computerized charger/dischargers, sounds handy.
 
#10
The hobby club we are just starting is still talking about salt water baths. :( I have been looking for a better alternative and I think this is it. Thank you Samick. This is HUGE. :)
Don't use saltwater. It's bad and not correct. All you will do is corrode off the wires leaving the battery internally charged. If you permanently want to discharge a battery use a small lightbulb and leave it on.

See this thread for additional details.

For a 1s battery that small, don't hook it up to a 1A source. Maybe 1mA. When trying to revive a battery you're fighting the internal resistance when it's over discharged. The power eaten by that resistance is represented by I[SUP]2[/SUP]R, and with a higher than normal resistance and a high current you will get more power dissipated in the form of heat. Start very low, and then slowly step up over time. See this article for details.

My personal advice. Chuck the battery and get a new one. It isn't worth the dangers and hassle.
 

cranialrectosis

Faster than a speeding faceplant!
Mentor
#11
Don't use saltwater. It's bad and not correct. All you will do is corrode off the wires leaving the battery internally charged. If you permanently want to discharge a battery use a small lightbulb and leave it on.

See this thread for additional details.

For a 1s battery that small, don't hook it up to a 1A source. Maybe 1mA. When trying to revive a battery you're fighting the internal resistance when it's over discharged. The power eaten by that resistance is represented by I[SUP]2[/SUP]R, and with a higher than normal resistance and a high current you will get more power dissipated in the form of heat. Start very low, and then slowly step up over time. See this article for details.

My personal advice. Chuck the battery and get a new one. It isn't worth the dangers and hassle.
That's why I am happy we can 'chuck' them responsibly at Batteries Plus. It is my intent to permanently stamp out the stupid rumour about salt water baths being a 'responsible' means of destroying old Lipos.

Radio Shack took them but is now gone. Batteries plus offers no hassle and an option for the school and the club.

Chucking a lipo in a landfill is as bad if not worse than the salt water bath. I can see a garbage truck fire started by this and the UGLY news report that will follow.

Thank you Batteries Plus! You give me a responsible solution that doesn't require kids or garbage men to be proficient with a fire extinguisher! :)
 

jhitesma

Some guy in the desert
Mentor
#12
Never heard of batteries plus...just looked them up and the closest one is about 3 hours from me :( We do still have our Radio Shack though, shocked that it didn't get closed in the bankruptcy, usually our stores are the first to go in those cases.

I have a metal bowl full of old batteries awaiting disposal. None of them have any charge left but are still waiting for me to scavenge their XT60's before I'm ready to get rid of them. Even though they're completely discharged and therefore should be safe I still keep them in the metal bowl, on top of a metal structure outside away from anything flammable.
 
#13
Wow you're lucky, we lost all RadioShacks here in manhattan… Not many stores like it around, I have to go deep into queens or something for stuff like that… or china town but I'm not familiar with the reputable stores there.