more than one year ago I bought from HobbyKing 2 Lipos for my Copter... unfortunately due to personal problems I never get to start building the copter and never used them.
Now I was starting to look into that things again, and I was checking everything I had, and I found out that one of them is a bit inflated: not like a balloon, but if I press I can feel the finger going down at least a few mm.
I never charged them so they are as the came from HobbyKing.
I have 2 Turnigy Zippy 2200mAh 3S 25C
Actually I also have a "transmitter pack" 2500 mAh 3C S3, still from Turnigy.
I've checked the cells with a multimeter:
for the healthy batteries the total pack is 11,5V with each cell 3.84-3.85 V each.
The puffed battery has 2 cells with 3.85 V while the 3rd one (actually the one where I can feel the empty space) is 0.6V.
What should I do with that one? Can I use it or recharge it? Shall I dispose it (if so, where should I bring it)?
For sure dispose of it! Do not try to charge it...
Puffed Lipo are dangerous
Hobby shops will take them from you, sometimes for a small fee. But they will dispose of them correctly.
Too bad my hobby shop doesn't do that service :(
Unfortunately the battery with the cell that measures 0.6v is damaged and must not be charged, discharge the other two cells and then dispose in accordance with your countries local regulations.
I've attached a couple of good guides from http://www.4-max.co.uk
that will help you understand how to look after lipo's and prolong their life.
Thank you very much.
So I just discharge them normally with the normal charger/discharger? Doesn't the puffed battery risk to explode now that is damaged?
I just found this document that says that if a battery is damaged it should not be discharged:
Don't discharge using your charger.
If you can discharge the two remaining good cells by shorting with a car sidelamp as suggested in the do's and don'ts, but if your not confident with this then place them outside on the earth, in a sand bucket, or in a metal biscuit box somewhere safely out of the reach of children, and leave to loose charge naturally until less than 1v, then if local regulations permit, place in household refuse, or by all means follow the guidance given in the Thunderpower document.
Ok, thank you
It's not the easiest thing to discharge the cells individually via the white ballance connector, so instead take outside and connect to a receiver, speed controller and motor as normally using the red and black plug, then run the motor at a slow speed until the voltage drops away.
Do this in the open and away from anything flamable.
Once discharged check that the pack is not getting hot, leave outside for about 2 hours, then take along to a battery disposal point if this is provided at you local waste disposal site. If this is not available wrap in a wet newspaper and dispose with your non-recyclable household waste.
The salt bath method I think, is a way of both dischargeing and rendering the pack environmentally safe for disposal in landfill.
Don't discharge a puffed li-po using an esc and a motor.
The only way to discharge a puffed batterie is using the balancing connector.
If you can't connect anything on the balancing connector, take out all wires on the connector and discharge the cell with a car lamp.
The boyfriend of my sister tried to discharge a puffed 2S li-po using his esc on his savage....
The li-po started to smoke after 3 minutes. After 5 minutes the savage was burned.............
Thanks for that correction Perecastor.
You guys are over-complicating this. No need to discharge, that is what the salt water is for. Go outside somewhere safe (sand or concrete floor). Wear some thick rubber gloves and make some holes in the battery all the way through with a screwdriver and a hammer (battery may smoke a bit when you do this, and there is a theoretical chance is will start burning. Hence the firesafe floor). Then put it in a bucket of saltwater and leave over night.