Bad battery?

One of my IRIS+ batteries (which is original 3DRobotics) is behaving strangely when plugged into the charger. The e4 SkyRC charger “charge” light is off and the 3S cell LED is flashing. All other lights are off.

I checked the manual and there is no condition where the charge LED is off and one cell LED is flashing.

Anyone seen this? Is this a bad battery?

If I plug my other battery in the charger behaves correctly and the charge LED turns amber with one of the cell LED’s flashing and the other two glowing (indicating that it’s in CV mode and one cell is discharging).

Thanks.

Answering my own question. My guess is that I discharged the battery too far - beyond the recommended 25% - and so the lipo charger won’t charge it. The way I did this is to leave the drone plugged into the battery while I had Mission Planner connected to it (yes I know USB can power it) and that fully discharged the battery until it shut off. So don’t do that.

There’s a trick that the Internets says I can do which is to connect a NiMH charger for a few minutes at 11v and low amperage to bring the voltage back up on the battery. So I might do that and try not to get lipo shrapnel all over me.

rcgroups.com/forums/showthread.php?t=1074181

Replying to myself again. 3DR was nice enough to RMA the bad battery at no charge including shipping. Very cool company.

Mark.