Discharging LiPos while checking voltage

[radiomikey]

I think I may have just learned something. I had a lipo at 100% which I needed to discharge for storage. I connected it up to a monitor and also a small charge checker so I could monitor the discharge. What happened was that the status stayed at 100% then the battery died and went ominously puffy. Obviously I'm taking the precaution of decommissioning the battery but is there a fundamental thing I don't know here that I shouldn't have done what I did?

 

[kloner]

you didn't want to discharge it all the way, never more than 80%. you wanted to either go fly it a few minutes to knock the excess voltage off the top or hook it up to your battery charger and go into storage mode. either way, your looking to store it at 3.8 volts a cell

 

[radiomikey]

80% was my target. How come the checker carried on reading 100% and appeared to nuke my battery?

 

[radiomikey]

p.s. sadly no storage mode on my charger. That's definitely the next upgrade though

 

[kloner]

i'm not sure what the checker is? if you mean lipo alarm, it shoulda been beeping for a while, but even they go quiet after a while when theres not enough power.

 

[radiomikey]

Nope - just one of these guys http://www.lightinthebox.com/rc-cel...?currency=GBP&litb_from=paid_adwords_shopping

 

[kloner]

That's a tool for checking cell voltage... nothing to do with a controlled discharge....

For what it's worth, all you had to do was hover your model for a couple minutes and it'd have been right at storage levels.

 

[soler]

That tool takes a few readings and averages the voltage and then displays it, it does not update as the voltage drops

 

[radiomikey]

Thanks soler. Is it normal that discharging the battery to zero left it puffy? I knew total discharge is potentially unrecoverable but was surprised by the chemical breakdown.

 

[soler]

Yes, once it gets like that they are dead