My son has 2 soft pack 3 cell lipos . One is puffy in the back the other is puffy where the wires go in. They are for his r/c boat. Is this bad or dangerous ?
He is 9. Should I toss them out or it's ok?

Thanks!

All lipos puff eventually, just be careful that they don't puff even make, make sure you don't ever charge them and watch for cracks were you can see the cells.

Thanks, but did you mean over charge?

Must have

Get rid of the puffed lipo. seriously. As a racer, a good friend of mine lost his entire car due to a puffed pack. normal charge and usage, all you seen was a fire ball going around the track. Be safe about lipos, once puffed they are very unstable

Depends on extent of puffiness. Slight puffing is ok in my book however if the packs are puffed up all over then absolutely toss them out. Not worth the risk.

Not sure I agree that all lipos puff if taken care of properly. I have quite a few going back a fair ways, the vast majority don't have any visible swelling or puffing. My take is over discharging is perhaps the most common contributor, and sitting charged too much.


Personally I can't see taking much of a chance, especially with a 9 year old being around or working on the car. Lipos are available pretty inexpensively if needed, and are consumables anyway.

Agreed 100%

I have had and still do , some lipos that have slightly puffed. In my case it seems it's from running too low of a c rating which overworked them that made em puff up. I've never over charged Lipo but I've found that in a boat they pull lots of amperage. There's also no cooling unless you get a cooling mount plate for them.

ok, I saw this 2 weeks ago at the track. A local sponsored guy puffed a pack on the track. After the race, he put it in an ammo can. About 10-15 minutes later we heard the boom and smoke. It almost sounded like a gun shot in that ammo can. Lots of fire and smoke. Keep in mine, they can start fire when non in use or charging. I get rid of puffed packs. Some guys say, "I have used puffed packs for year and its fine". Why risk it? Puffing is not a good thing and you have a kid using the model. I race offroad with my 8 year old, so I will never own a puffed pack.

Not quite true, all Lipos do not puff. Once it's puffed throw it away, they don't heal themselves and only get worse. There's a reason that ROAR disallows any puffed pack from racing no matter how slight.

Lipos puff mostly from user error unless you bought it puffed. Most likely is leaving them unused with a full charge for more than a few weeks. Next is using a low discharge pack under high loads. A boat is a high load since it's running at full throttle most of the time.

I felt the same way, this just backs up my thoughts.
$100 is not worth the chance.

Always better safe than sorry with kids....and I agree most "puffed" lipos have been damaged by over charged, discharged too low or have been used in an improper application (too high of a current draw for the pack)

I do not overcharge my packs....I use a storage charge during the off season or when I am not racing for a few weeks.... I have lipo cut off on all my Esc's....... very very rarely do my packs get ran long enough to get anywhere near the low voltage cut off. I balance charge my lipos every time, many peope think that's ridiculous and only balance once a month or something like that....I balance EVERY charge and if I cant get a pack balance charged between races I switch packs.... I can be a little anal with certain things and after all that my soft packs still have a slight "rounding" usually I notice it developing after using them regularly for several months.

I think all lipos with age & use will develop some slight "rounding"....I am talking a mm or two at most.....I feel they are safe to use...they balance well and quickly on evey charge, they take the right mah compared to newer packs....no sign of an issue at all. I have had packs "puff" more than I feel comfortable with and they have typically shown it by taking longer than normal to balance and when I plug it in the charger shows that one cell's voltage is off verses the others.....These were the packs I usually used for bashing in a monster truck...ran in snow, water, heavy loads for long periods of time....and they were replaced immediately

I have soft packs that are over a year old... and some are well over 2 years old, I just dont use them regularly any more after switching to hard case in everything.......but many of them have slightly "rounded" over time....It's much easier to see the "rounding" on a soft pack......I would not say they are "puffed" but they are no longer perfectly flat.

I have seen people use lipo I would call extremely "puffed" they are very noticeable rounded and barely stay on a pit table without rolling away No way would I put one of those in my vehicles.

One thing I have noticed on hard packs.....I have opened several hard packs that have room between the cells and the case, so they could swell several mm and not even touch the harcase, so there is no way to see if they are starting to "puff" or not until its pretty noticeable.....I have opened others that the cells literally press tightly againt the case and you could barely get the case on....so even a very slight "rounding" of the cell shows on the case....also some hard cases are much thicker and stronger which would be less likely to show the "rounding" as early

So I have a hard time using the appearance of a cell as the only factor in judging its condition.....I watch the individual cell voltage, charge time, balance time, mah input etc..

Long story short.... if you have any doubts get rid of it....but to say "any puffing at all" means its bad is pretty vague and leaves way too much room to personal interpretation.