Tripped my Aw 14500 PC. How do I charge in parallel?

ky70 · Jun 21, 2010

Hello folks,
My Nitecore D10 cut on in my pocket Saturday (while I was out of town and away from my charger). When I noticed it on, I cut it off and thought nothing of it as I was sure I would have felt the light on in high in my pocket (especially with me wearing linen pants). When I tried the light later I noticed it was acting funny and would only cut on in a lower blinking mode (which isn't part of the UI)...so I figured my battery was weak and I checked it with the mutltimeter and the battery read 1.3v. Yikes!

So when I got home Sunday night I tried to charge the battery and it would not charge in my wf-139 charger (light stays green). Did a little reading and saw that a tripped batt might be jump started by parallel charging. Now I have 2 questions.

- Is my battery damaged by being in this over discharged state for going on 2 days?
- Are the pics of charging batteries in parallel? I see that a paper clip can be used by touching both the positive and negative side of the tripped battery and the "good" battery, but I can not picture how this looks in the charger.

Thanks!

jasonck08 · Jun 21, 2010

Yes the battery is toast. Anytime a Li-ion goes under about a 3.2 or 3.3v resting voltage then you've gotta toss it. Even if you did manage to get it charged up, the capacity an safety of the battery would have been compromised.

Do you think you could have left it on for a few hours on a lower mode setting? There is a minimum current draw that the protection IC will kick in at (sometimes 200ma current draw or so). Either that or the IC is defective on your battery.

ky70 · Jun 21, 2010

jasonck08 said:
Yes the battery is toast. Anytime a Li-ion goes under about a 3.2 or 3.3v resting voltage then you've gotta toss it. Even if you did manage to get it charged up, the capacity an safety of the battery would have been compromised.

Do you think you could have left it on for a few hours on a lower mode setting? There is a minimum current draw that the protection IC will kick in at (sometimes 200ma current draw or so). Either that or the IC is defective on your battery.

Thanks for the info. I'm not really sure what happened, but I know the D10 was in clipped in my pocket all day and when I saw it on in my pocket, I pulled it out and turned it off. I know it was not on long at all because the light was on high and my D10 gets hot to the touch if it runs on high for over 5 minutes and the light was still cool so I know I caught it early. But what happened to the battery I don't think I'll ever know but I do find it very odd that the battery voltage would be that far below the overdischarge cutoff point. The other irony is that over after about a month and a half of pocket carry, this is the only accidental turn on I've had with the D10.

Thanks again.

malow · Jun 22, 2010

once upon a time i left turned on a flash receiver with 2 10440 li-ion on it.

the batteries measured 2.3v.

now, after recharge, the voltage falls from 4.20V right after charger, to 4.05V after a few minutes.

then i compared the runtimes with other batteries, and the battery now have about 30% less capacity thant the others ones.

so, yes, "that thing" about do not over-discharging is very real. :(

protection circuit is the way to go.