Help me revive a 16340 can it be done?

[hyperloop]

Hi all, i'm quite hopeless when it comes to electronics so i hope you all will bear with me.

One of my trustfire protected 16340s just up and died on me, measurements showed that it had dropped to 2.88 volts when i put it in the WF 139 charger that i have, the light immediately shows green, i.e. fully charged but when i check it still reads 2.88 volts.

any way to save the cell?

 

[sparkysko]

Might be possible. Could try to find an RC enthusiast that has a nifty charger. Some chargers don't like touching things below a certain threshold. I've switched to nimh mode on some chargers to try to 'bring up' a pack, and then switched it back over to lithium mode once it's in the 3.0+ volt range.

I've tried to use my super computerized charger on some over discharged lithium cells and they quickly ramp up in voltage, and quickly drop it again as soon as you stop applying power. If that's the case, then just chuck it.

Test the voltage while it's charging and find out if it ever gets to 4.2.

 

[45/70]

hyperloop, I'm going to suggest something here that you will have to do at your own risk. You may want to have your phone handy with 911 all punched in and ready to go, but really, I don't think you have to worry.

If you have another 16340 cell that is somewhat discharged, but not anywhere near the discharge state of the cell you're trying to revive, place the two cells next to each other on a metal surface, top (positive) side down. I use the stainless edge around my kitchen sink. Hold them in one hand and short across the negative ends with a fork (hey, you're in the kitchen, right?) for 1-2 seconds. Then check the voltage of the cell in question. If the voltage reads above 3.0 Volts, stick it in the charger and see if it starts to charge. If the voltage is below 3.0 Volts, repeat the process with the fork etc. I wouldn't do this too many times, the cell could be bad, but eventually, I'm betting you'll get the battery to charge.

Good luck!

Dave