i was charging up my lipo batteries for my belt cp..........i accidently left the charge rate on 2.2 amps after charging a 2200mah battery. I nearly finished charging a 1800mah on 2.2 by accident and looks as if the silver outside underneath the green covering on the esky battery has bubbled. is this still safe to use?

Safe answer - NO, dispose if it properly and get a new one. Once a Lipo battery puffs it is potentially unsafe. I haven't always followed this advise but that is what the manufacturers say. They also say to charge and store in a fire proof container and handle all batteries as if they are made of TNT. (sarcasm inserted here).
I know that is not the answer you wanted but the safest thing to do would be to soak it in salt water for 2 days (after discharging) to rendering it completely dead and then recycle it.

The safe answer is no you should not continue using it as it has puffed. You will continue to lose performance IF you keep using it anyway. To dispose of safely, dicharge as completely as possible then soak in water saturated with salt for 2-3 days then throw in the garbage.

Just a follow up. Even though soaking it renders it safe, it is best if you can recycle it. They contain heavy metals that are not so great for the environment. Radio Shack will take dead batteries for recycling. So will some other places. Please try to recycle it, not just throw it away.

No they dont.
Your thinking of nickle/cadnium batteries.
Lipo's are made from lithium.
Second lightest metal next to hydrogen.
The salts they form are relatively harmless.

I have been using a puffed battery for 3 months now with no loss in power or flight time(1350 XMseller special). Even when i charge it, the cells stay within .050 of an Amp from each other. I went to my LHS and showed him the battery. He told me puffed batteries are not any more dangerous than a non-puffed battery but that the life-span would most likely be diminished. I would recycle only if it has physical damage, like a hole.maybe even if the cells are not closely matching anymore on a balance charge. Seems like this is another issue that has opposite opinions that work. I can only go on my experience of course, but I would keep it...Always use caution when charging, even if the battery is in perfect shape.

Z

ok then, thanks for all the replies. I will use it seeing it is charged then dispose of it properly. Looks like its time to stock up on some more haha