Got a buddy that has a couple slightly puffed lipos. They read almost at spec and charge and run no problem. Is it safe for him to keep using them?

See also: Russian Roulette

hahaha! exactly it's just safer to toss em and pick up a new pack if one puffs

Depends on how much attention you want to pay to the lipos.

If it's slight? It may run for one or two more discharges, or it may run for two more years.

The risk? Battery smoke, possible fire, and Hydrofluoric Acid about from the LiPo decomposition.

The reward? Not having to buy new batteries. But you'll have to always, always keep an eye on those packs. They are suspect FOREVER, until you throw them out.

I myself have vented puffed packs and built working packs out of the remaining good cells in "bad" packs. However, there's a certain amount of responsibility you have to assume in doing these things. There's a "Right" way to do even the "Wrong" thing.

I recently "vented" one cell in a 3s 2200mah soft case pack. I used a small 23 guage hypodermic needle and barely pierced through the plastic. Some clear acid came out. I squeezed the pack to get some more out, wiped it dry, and then put shoe goo on the tiny hole. I tried to squeeze the shoe goo into the hole with some finger pressure and I think I succeeded. It is not leaking and that cell is not puffing. I have used it for 4 cycles and so far, so good.

WindDrake, or anyone, is this what you mean by venting?

By doing this, I assume I have reduced the internal pressure. Does that extend the life of a puffing pack?

Pack puffing is caused by Hydrogen buildup in the cell. Yes, flammable gas.

Normally, the Hydrogen is redigested by the electrolytes and responsible catalysts in the cell chemistry, but over-discharging, heavy use, age, or just plain poor quality can cause chemical issues to develop.

Normally you don't want any stuff from inside the cell. That's electrolyte. When venting a pack (Releasing gas buildup), try and make sure your vent hold is facing up, so anything oozing around inside the pack doesn't come out.

Disclaimer: This isn't inherently safe. Please realize you are playing with acid and fire when doing this. Do it outside, where you can throw the thing away from you if something goes south.

soo your saying that if a lipo pack gets puffy its safe to poke it with a needle to vent it? is there a youtube video out there that you know of?

Oops, I didn't see that I had got some responses to my question. I started another thread with the same question titled "Repairing, 'venting' a soft case LiPo".

See my post again.

Bolded for effect.

Messing with the guts of LiPo batteries is not safe. However, this doesn't mean you can't still mess with them, just realize the sort of spot you are putting yourself into is not kind if things go sideways.

Sideways could be East, West, North, or South couldn't it?

Please throw it away in recycle bin NOW.. I think its bad for user and anyone around u..

If its a mm or two i feel its ok to keep using. More than that and toss it..

Is it not better to safely discharge the battery in salt water before discarding? Venom recommends cutting off the leads one at a time and submerging the battery in a bucket of salt water for a day. This allows it to safely discharge without lighting up. Throwing away a puffed pack is like chucking a smoldering firecracker in a trash bin.

Absolutely. Always discharge them before hitting the trash.

Also, keep in mind the elemental Lithium in the pack is what causes the fire on contact with air. Even a discharged pack will light up when it's finally punctured. But when it's empty, the result is far reduced.