18650 - can't get voltage reading

[Glorious1]

My wife was given a new Olight with an Olight 18650. We're expecting a storm, so I want to make sure all batteries are charged up. I took the battery out to read the voltage. It just jumps around in the mV range, no real reading. I have two other 18650s and they are giving me solid, reasonable voltage readings.

The Olight is new, and the flashlight works fine and gives good light with it. What is going on? I'm afraid to charge it (even though I have a Pila charger).

 

[adamlau]

Try resetting the protection circuit by tapping the postive terminal against the positive terminal of a fully charged cell, negative against the negative.

 

[Glorious1]

Thanks for the reply. I'm not clear if that should be done sequentially or at the same time with two charged cells. Anyway, I swallowed hard and put it in the charger. It seemed to charge normally, and when it was finished it had a good solid voltage reading of 4.18. Perhaps the charger reset the protection circuit as well.

 

[sledhead]

I've had that happen. Put it in the charger and check it every now and then.

 

[ChrisGarrett]

Parasitic drain depleting the battery, over time?

Full cell nose to nose with the dead one and while holding them there, short the negatives with wire or a straightened out paper clip, for resetting the PCB, but if you're getting a positive reading on your meter, my first point might be the case.

Chris

 

[WalkIntoTheLight]

I wouldn't want a light (or battery) that resulted in that extreme of a parasitic drain.