Puffed Cell in 2S and 3S 3400 Zippy K ???

[Raze ST Truggy]

Here's a post that I made over at the Hobby City customer community:

"I've made two orders from hobby city and would order again. The first order I got 2 3S 4300 Zippy K Lipoly's and the I max B8 charger. The second order I got 2 2S 4300 Zippy K Lipoly's and some other odds and ends. The first order was May 11, 2008 and the second July 16, 2008. I immediately put a deans connector on one of the 3S Lipoly's and charged it with the Imax-B8 and proceeded to use it in my rustler.

Fast forward to today.

Last week I put deans on the other 3S and the two 2S packs. I charged up the 2 2S packs and one of the cells wouldn't balance out. Best I could get was 4.20 and 4.06 on the one pack the other got 4.20 and 4.20 verified by a multi-meter. I ran the 2 2S packs in parallel for 4S in my rustler and the bad cell went dead. 0.34v

Now to my question, is this my fault for letting them sit two long? I kept and eye on the voltage and they bother were ~85% charged while just sitting. Are they under type of warranty?

One of the cells in the 3S pack that I did use puffed while sitting unused for a month or so. That was also stored at ~85% charge. Why did my cells puff? Why wouldn't my balance charger balance the bad pack? The pack was brand new.

-Brian"

Did I kill these cells becasue of letting them sit unused: The date bought and used are both above. Can someone explain to me why a cell being .1 doff of another cell in that pack it is such a problem? thanks

-Brian