Hi!
So ive never heard of anything like this but I have two battery packs that I have done this with. One is a traxxas 2s 2200mah 25c and one is a powerhobby 3s 5200mah 75c battery.

So these two batteries, both relatively new, puffed up pretty bad. It just feels like air in the shrink wrap and when I squeezed them, I was able to squeeze the air out of the shrink wrap leaving the packs in "like new" shape and size with perfectly flat cells... If I was squeezing air out of the cells wouldnt that be exposing them to air and they would start on fire or could I just be squeezing actual atmospheric air out of the shrink wrap? At any rate, it kind of sketches me out. I have other puffed lipos that I'm not able to do this with ("normal" puffed packs). Ihave 20+ lipos so I'm not entirely new to the lipo scene but this is interesting. Thoughts?
Thanks, Nick

toss. only way for packs to puff is to go through some sort of chemical change. Even if physically they can be returned to the normal shape they will never be the same.

Sometimes you can get the swelling to go down if you place the packs in the fridge.

what car + motor are you running? Sounds like the packs aren't properly matched for the current you're pulling

Well i know more than a few guys who run lipos that are a little puffed up but if any more toss it they loose a good amount of punch anyways.

True. How much puff we talking about? A little is okay. More and the batteries are pretty much done.

I run a Losi Xxl2e with the 75c batteries, stock motor/esc and gearing. The traxxas battery I'm running with the mini e Revo. The traxxas one doesn't surprise me, all of their batteries puff on me. I've started buying SMC 90c batteries and they're phenomenal. I run them in the xxl2e, my 8ight te (even geared at 80mph), my slash on 3s and my proboat. No problems at all.

It's a pretty good amount of puffing. Enough for powerhobby to warranty the battery via picture. Maybe 3-4mm? That's a guesstimate. But I can squeeze the air out....that's what's messing with me big time lol. I've never been able to squeeze the air out of a lipo. And I can do it every time i run it and it puffs up. It squeezes out to perfectly flat. As far as loosing punch, these packs still flip my xxl2e on it's back at 3/4 throttle and it's a big truck.