Bike Forums - Maintaining/charging a Ni-MH

Quote:

Originally Posted by rajman

Is this what happened to my Energizer NiMH AA's? I was in the habit of running them down to zero light, thinking that full discharge was the way to go.

I've used them for about 40 cycles, and now with a full charge they give a weak light on my halogen light (PB 5000x). It seems to me they aren't giving out the right voltage, but I have the same problem on the 'bright' setting (which should double the voltage).

Should I get a new set and just recharge them every time I use the light? When I was using the light/batteries last year, I could get 4-5 h from the lights before recharging (1 week of commuting), which may have caused the problem.

My understanding has been that it's ok to take any single CELL down to 0V, but to deep discharge a BATTERY is bad. From experience I know that once the light goes dull, one cell in a 4-cell pack has gone into reverse. That is, the stronger cells in the pack are charging the weakest BACKWARDS. You can verify this easily with a voltmeter.