Lipo batteries

[sone]

Trying to charge a couple of Lypo batteries that have been standing for 18 months without use and they don't seem to want to take a charge.
Are they likely to be buggered?. An idea how I can check?.

Cheers
Steve.

[Magic919]

I'd probably just try charging them :-)

Do they show any voltage?

[grenpayne]

Lipo battery chargers will not charge packs that are less than 3.0v per cell. Get a voltmeter/multimeter on them, and see what they give. If they're lower than that they're not necessarily buggered, but the lower they are, the higher the chances. Also, are the packs puffed up at all? If they are then they are most likely they're past it unfortunately.

If your packs are less than this there is a way to charge them but you have to be really, really careful. Do a search for charging a flat lipo, there's loads of info on the net and you have to have a charger that will do NiCads or NiMH packs. And please only do it if you know what you're doing!

[sone]

Thanks for responses. I've tried just charging them but the charger sort of trips out and goes back to it's original screen with no fault notifications etc.

[clockworks]

Pics of the charger and batteries?

[Conian]

Can you fool the charger into thinking there is 3v by linking in a couple of AA batteries to get it going?

[sone]

Conian said:

Can you fool the charger into thinking there is 3v by linking in a couple of AA batteries to get it going?

Am I going to blow up in the process?.

[Simond S]

At your own risk, and outdoors (but i have done it a few times).

Short your lipo's over a 12 car battery. This will give a little charge into the lipo and hopefully the charger will then see the battery.

Does the same as charging for a minute or two on a Nimh charger but saves spoofing your charger.

NEVER leave a lipo charging indoors unattended.

[theshrew]

Simond S said:

At your own risk, and outdoors (but i have done it a few times).

Short your lipo's over a 12 car battery. This will give a little charge into the lipo and hopefully the charger will then see the battery.

Does the same as charging for a minute or two on a Nimh charger but saves spoofing your charger.

NEVER leave a lipo charging indoors unattended.

Kin ell you is a crazy mofo :-o

I agree never leave one on charge

[Le TVR]

Do the following outdoors.

Connect to a NiMH charger set to 100mA and give them 20-30 seconds.
Disconnect and check if voltage is 3,0 or more and stays there.
If not repeat for another 30 seconds, measure again.
If it recovers to 3,0 V or more and stays there put it on a LiPo charger at LOW rate and check.
If it hasn't recovered it is probably dead.

Edit to add that's 3V per cell!

[sone]

Sorry I haven't made myself clear. Although I haven't used the batteries they did hold some power which probably had the heli running for a minute or two before giving up the ghost.
I've got two batteries but both don't want to take a charge on board. Once I press the enter button the counter starts on the charger and then trips out after just a few seconds returning to the home screen.
any ideas?.

[Le TVR]

What the charger is doing is typical if the cells have dropped below 3V each.
But it does seem unlikely that both LiPo packs have gone.
Have you tried another charger?
Is it possible that the ESC is faulty and the cut-off voltage is too low?

You really need a digital voltmeter to check exactly what each cell has gone down to.

[Simond S]

unplug the balance lead and try a normal charge.

hopefully you'll get some charge in there that will then help keep the charger happy.

if you have a Balance mate type device get some charge in, then use that to equalise the cells.

[sone]

Ok thanks, I think a trip down the model shop is in order!.

Thanks again.

Steve

[MrBrightSi]

I've used Lipos for airsofting for a while, i cannot stand the things. This is a reason why, they are such a diva way of holding electric. Can't you use nicads?