Hi,
I have an orion 3600 lipo which I bought second hand, but boxed as new, a while back. The lipo has died but hasn't swollen and looks normal so I've stopped using it, the reason for it's death being a combination of things from what I can tell...I thought I'd post some details as a warning to others having learnt the hard way!
1) Over discharging - Not using a cutoff! Which I knew was bad, but I only run at a club and top up, worst case every 2 heats, but normally every after every heat, which I figured was minimising the risk. I run a novak GTB (old one without lipo cutoff) & 10.5t brushless in a b4, so I figured not the most power hungry of setups.
2) Shorting it out a few times - Disconnecting the wrong end of the charging cables when rushing and momentarily shorting the pack, again I know this is bad, but when your rushing around at a meeting the stupidest things can happen unless your really careful!!! When using NiMH cells and open contacts you HAVE to be really carefull with ALL the handling, fully sealed lipo's look much safer, but there are still some risks to remember!
3) Possibly overcharging it - My charger is a Intellipeak ICE, and a has a charge capacity setting on it. I had this set to 110% (left over from the old NiMH setting I used to use before I changed it to CC-CV charging the lipo). Also, I wasn't balance charging either.
So, I'm not sure which of these has been doing the most damage, but all in all I could have treated the pack better and thankfully the pack has died gracefully rather than going bang.
The pack has been sat idle for a few months now, and this morning out of curiousity I measured the voltages accross the pack to see what it was at before disposing of it.
Measured across the main + & - the pack measures 4.06v, well below the minimum 6v for a lipo. I then measured + to balancing port at 0.009v, and balancing port to - at 4.06v. The other good packs I have measure evenly accross the balancing port as you'd expect. Clearly I have a very dead cell in the pack!
So now I'd like to dispose of the pack, knowing I've learnt a few lessons about lipo's.
The main question I have is...I'd like to discharge the pack properly and safely before I bin it, but being as I have a very dead cell in the pack, would discharging the pack very slowly on my ICE be a safe thing to do?
Sorry for the lenthy post, but I thought some details would help.
Cheers
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