How to Keep NiMH's From Loosing Charge

dont last long, and if theyre new, dendrites probably arent the problem.

Hmmm. I have had very good results for a long time with that technique. The issue is that you have to recondition the cell before using it again. If not done it will fail really soon with new dendrites. Newer cells are more prone to this than older cells. It also is a lot less helpful on NiMH than NiCad.

?-)

Interesting. What reconditioning process do you use?

NT

Batteries don't "loose" charge, they looze charge.

If they roll around lose they do :)

NT

...and sometimes the get loost under the couch.

in

cells dont last long, and if theyre new, dendrites probably arent the problem.

technique.

again.

are

The baseline is to completely discharge the cell with a saturated bipolar transistor. Let it cool down some and charge it back up at C/10 Max current and watch the cell voltage for endpoint. Maybe repeat one time.

?-)

"josephkk"

The baseline is to completely discharge the cell with a saturated bipolar transistor.

NiCd and NiMH cells can deliver very large currents - since the internal resistance is in the tens of milliohms. AAA cells can deliver over 20amps, AAs up to 50.

So you need a series limiting resistor ( say 0.22ohms, 10W ) to be safe, even with one cell.

Let it cool down some and charge it back up at C/10 Max current and watch the cell voltage for endpoint.

However, both will get warm at the end of a slow charge.

.... Phil

Thanks folks. I think I may try that

NT