Swelled batteries is a sign of badness.  It can mean anything from the capacity being slightly down to the battery being ready to burst into flame.

Given how we treat our batteries, we should always store them as if they're ready to burst into flame, so all it should mean is that you shouldn't be surprised if they don't last out a full flight like they used to.

I don't fly lectric for many reasons, but I have a lot of experience with Lithium batteries .If I owned a poly-lite battery I would do as Fred suggests. BTW, a factory rep or lawyer or factory engineer will tell you. "It did NOT explode, it just released it's energy quickly"

yah.....be careful

If the pack is working, put it in your beater plane and reduce the flight time.

I flew with a swollen battery for a while and once, while testing some props, it shut off on the low voltage cut off. The swollen cell was too low to charge and wouldn't even charge up on the Nimh setting. I saved the battery because it had 3 good cells and a year later I had a cell in another battery go bad. I took a good cell form one and replaced the bad cell in the other and now I have a good battery pack again. If you can solder carefully unwrap the pack and remove the bad cell. Be very careful separating the cells, use a few drops of lighter fluid to soften the glue and make a thin spatula from 1/8 basswood with rounded corners and work very slowly. You don't want to bend or dent the cells.



MM