carlbellybutton10

Ok so I have two Flightmax 5000mAH 30c lipo batteries, a common sense balancer pro and an onyx 230. Last time I ran them was about 7 months ago and i didnt get to fully discharge them fully because i broke one of my axles. So I guess my main question is are there any specific precautions I should take before I charge them again? When I plug my balancer, it doesnt show any voltage (nothing lights up or anything). Still kinda new to this whole electric thing. Thanks for any advice/help.

FoamyVictim

Put them on a concrete surface(or in lipo safe charging bag) and try charging them. If they take a charge, you should be ok. In my experience they don't like to sit for long periods with no charge. I always store mine charged. There's one way to find out, charge and use them. Sometimes that's the way to bring them back. Make sure you balance charge every time.

Foxy

Lipos need to be stored at about a 40% charge. If they were almost flat when you stored them, they will likely not take a charge. Cycling may help, but I doubt you'll ever get the same capacity out of them again.

So yeh, when you know you won't be using the cars for a couple of months or more, give them a storage charge (my charger has this mode) around 40%, and they should be fine.

damroadhog

Save that lipo !!!


Most of the time you can bring back a lipo from the dead, never had any bad things happen doing this BUT, do it out in the yard , not in the house.

let's say you have a no voltage 11.1 V pack , take a good fully charged 11.1 V pack and parallel plug, plug the good pack to the bad pack and let it sit for about one min, if your pack is going to come back it will within that time. This should get your pack up to or just above the low voltage for charging.
I have jumped a 11.1V lipo with an 14.8V lipo for a few seconds and this also works, no bad things happend, I have not left them connected any longer than a few seconds . Best to stay with the same voltage packs.

That bttery may never be as good as new but it will come back, always balance charge at the lowest power setting you have.

Or just buy a new lipo, they are cheap now.

Maj_Overdrive

My Feedback: (11)

Jumping packs like this is never a good idea. I know you say you never leave them connected for more than a few seconds, but it is not good for either pack. Direct connecting packs like this leaves only the resistance of the wires between them, which is basically none. The "low voltage pack" will draw on the charged pack very hard, past its "C" rating, and the low voltage pack will be charged faster than its supposed to be as well. Packs should only be wired in parrallel when the voltages are as even as possible to prevent one pack from drawing on the other like this.

The best course of action in this case is to first verify the voltage of the pack and each cell. If they are below 3.0 volts per cell, most lipo charges wont charge the pack. In this case, switch to NiMh mode. Charge at half the normal charging amperage and check the voltage of each cell every minute or 2 until every cell is at or above 3.0 volts per cell at which point switch back to normal Lipo balance charging. If you have one or more "low" cell in a pack its important to check cell voltages often to prevent the "high" cells from being overcharged and damaged while in NiMh mode.

For the original poster. You said your balancer only has lights, and I'll assume you don't have anything else to measure voltage besides the charger. Just watch the charger voltage and keep checking with your balancer while in NiMh charging mode. Once you see voltage registering on all the cells with your balancer switch back to Lipo mode.

40-50% charged is a good storage capacity, and some chargers have a "storage" charge built into them. For those that don't, 3.7 volts per cell is where you to be for storage voltage

carlbellybutton10

Seems kinda sketchy, might have to give it a try though. As they sit right now my charger wont even charge them. Has anyone had a lipo blow up on them? How much damage does it do/how big is it....you know just so i can be prepared if something happens?

t9dragon

My Feedback: (11)

Yes I had one go up in flames. The flames were about 2-3ft high and it burned hot enough to completely melt the plastic hard case that was around the lipo.

carlbellybutton10

do they just burst into flames or do the actually like explode?

t9dragon

My Feedback: (11)

Kind of an explosion/burst... You definately don't want it to happen indoors or you could burn your house down.

Foxy

[youtube]http://www.youtube.com/watch?v=6vYn2lbBh0Q[/youtube]

carlbellybutton10

Ok so its pretty obvious when its about to happen and not just going to sneak up on me HAHA. I think Im going to try that NIHM thing that was suggested earlier but Im going to wait for the morning whens its cooler outside and the batteries dont have to sit and bake in this 100* weather while charging