TF flame 18650 judgement call

I have a question for all of you with (much) more experience with lithium ions. Would you try to reset the battery from the following situation?

I heatsinked my UF WB-504b with aluminium foil, and carefully looked at the bottom of the pill through the body tube for shorts. I did not see any, nor any debris in the tube. I then put in a freshly charged Manafont Protected TF Flame (4.16V), and tried the light out. It worked well. I then went to bed, carefree and easy.

When I woke up the next morning, the light was dead, and the battery was reading 0V. I put the matching TF Flame in, and the light seemed to work fine. I still could not see any obvious short, but could have dropped some small debris out when changing the battery. I have since re-sinked the light, and it does not seem to drain batteries.

The 0V battery will not charge in the battery charger (UF WF-139), it just alternates between red and green, slowly. I have read that you can reset the protection on a cell by shorting it, then trying it in the charger again. I've also read that the low voltage protection does not always cut off, so this cell may truly be at 0V, and irredeemable.

Is it worth trying the reset? I'm pretty leery of these batteries until I get used to them. If I need to learn a lesson from this loss of $4, I'm prepared to do that. (I've learned a lot less from much larger losses in the past. ) But, I'm pretty frugal and don't want to recycle a salvageable battery. It only had a few cycles on it.

What would you do? Is it likely that a possible short like this would drain a midrange protected cell like this? Thanks.

It sounds suspicious, that it is 0.0V dead.

I´ve drained my batteries going to be recycled, they are not too easy to get to 0.0V. I would guess the protection is tripped or faulty.

I had an old laptop battery, at too low voltage of 1,4V. This is -> trash-stuff. Had my Xtar WP2 II and remembered it had some sort of revive or such.

It did it, very slowly charged it to 3,5V or so and then started normal charge. Battery was trash, no matter what, could keep only about 800mAh. But it could be revived to at least some state.

but in my opinion, i really don't think it is worth it. if it were me i would just recycle it.

Agreed. $4 is not worth the stress, let alone the hazard.


last night I tried to empty one already bad (ebay 1$) 18650 to trash it. It was peeled open, no + and - too easily available so I decided to drain it before.

It was hard to get it under 3V.

Several hours after 1A -> 500mA -> 300ma etc it still remained over 3V. (drain to 0V).

It was slightly warm, always bounced up in volts. Not hot, not warm, just slightly warm. Minor thermal runaway or what? Why keeping up volts so stubbornly?

I drain duff lithiums in a plastic bucket of salty water.

Try a reset and look very closely at the wrapper. Make sure it has no cracks or tears

0.0V really sounds like a tripped/dead protective circuit. I would first try to reset it by applying something like a 5V pulse cross the battery. If it still reads 0V, either the circuit is dead or the cell's voltage is so low that it immediately trips again.

The next thing to try would be to puncture the wrapper with a needle and measure the cell's voltage without the PCB in between. If the cell is still healthy (above 3V) you could just remove the PCB and its connection to the positive pole, re-wrap it and use it as an unprotected battery.

I just had a camerabattery 3.4 volt which would not charge. Read 0.1 volt.

Opened it and put 5 volt direct at the terminals of the cell for a short while

with a powersuply. Put it in the charger again and now it charge normally.

So Tido´s suggestion above may work.

Just charge it and see what happens

A huge Thank You to Tido and Nautilus... I just resurrected two different batteries with the 5V current trick!

I was dumb enough to use two XTAR 18700 cells with different charge levels in a multi-cell flashlight, and one of them tripped. My XTAR WP2 charger wouldn't charge it. So I found an old 5V wall wart charger from my phone, spliced open the wires, and touched the ends a few times to the 18700 cell... And just like magic the WP2 charger immediately accepted it.

Likwise, I bought a secondary travel charger for my Android, supposedly OEM, but I ran the battery dead and then connected the charger, and it somehow managed to trip the protection circuit. I have been waiting about 3 or 4 weeks for a replacement battery to arrive in the mail. I read this today and decided to try it. I taped the wires from the above mentioned cell phone charger directly onto the battery terminals, gave it 10 minutes, and I'm back in business!

Thanks a ton guys!