Lipo battery swelling

[deano43]

Hi all
I have a turnigy nanotech shorty 7.4v lipo battery that's starting to swell in fact I have 2 of them the other is fine but one of them ain't and the are charged at 5amps and always balanced charged so why is one ok and the other not

[Cardnim]

When you say its swollen, by how much?
Just increased slightly, or puffing right up?

[john333]

If I remember right you used to leave them fully charged between meetings, this is a bit of a no no, and possibly why one of 'Ems swollen

[deano43]

its bulged out both sides enough to see its swelled but with out pictures wich i cannot do now as i am at work its hard for you to tell .
john- yes i know thats a no no i remember you telling me at the time lol but to be honnest i only did that a couple of times and i generally leave what left in the battery after my last race on both sets of batteries and charge them up before i come racing on wednesday night so would the couple oftimes i did that make the battery swell (hope not ) or just maybe a duff battery ?

[Cardnim]

John is spot on, and I have been guilty of this in the past.
"leaving whats left after a race" might not be good either, as this might still be too much charge.

Your LiPo battery charger should have a STORAGE level on it, which takes the voltage per cell down to about 3.8v.
Use this if your batteries are going to sit for anything more than about 7 days.

Also, both my VAMPIRE saddle pack pairs swelled up ever so slightly under normal conditions and after only a handful of times racing.
Contacting Vampire about this, they told me that this is completely normal because the cells are big ones (5400mAh). Their advice was to continue to use them, but watch the swelling and if it gets any bigger at all, to contact them for replacement.

...that was over a year ago and they are still going great and never swelled up anymore.

Hope it helps mate

[deano43]

Hi cardnim
Thanks for the advice I will carry on using it and do the same keep an eye on it for now anyway