"Tom S" wrote in
nk.net:

"Jim Yanik" . wrote in message
.. .
Darmok wrote in
:

Hi,

I've got an older Norelco electric shaver, which has some kind of
'fast charge' ni-cads in it (haven't looked, but that's pretty much
what they had when it was made). Normally, it will recharge in
about 20 minutes or so. Well, after all these years, one or both
batteries is dying, and I need to replace them. I was thinking of
just putting in a couple of Ni-MH cells (these are 'AA' size),
because I know that they can handle a higher charge rate than
standard ni-cads. I've got some extras of both, but no 'high
charge rate' ni-cads (although, I'm pretty sure I could get some at
Tower Hobbies, or similar R/C model shop).

Anyone ever replace batteries in a Norelco (or other brand) shaver?
Anything I should be aware of or watch out for? Seems like it
should be a pretty straight forward procedure.

TIA



NiMH cells have a more complicated charge requirement than NiCd.

Jim, could you be more specific? Not to hijack anyone's thread,
but we recently replaced a 3.6V NiCd cordless phone battery
pack (600mAh) with 1300mAh NiMH's, and plan to use the
phone's base (150mV input)

I hope you mean "mA".

to recharge it. If we're careful to
time the recharges properly, what other complications could
there be?



Well,your cells usually still have a partial charge of unknown amount,and
thus charging for the "standard time" will overcharge the cells.
A proper charger will monitor the charge voltage and look for the small V
drop as the cells reach full charge,regardless of the original charge left
on the cells,maximizing cell life.

That's why they are "smart" chargers.
And from what I've read,you can leave the pack on the charger even after it
is fully charged. No "forgetting" and overcharging.

--
Jim Yanik
jyanik
at
kua.net