"Asimov" wrote in
:

"Jim Yanik" bravely wrote to "All" (25 Aug 05 23:17:16)
--- on the heady topic of " replacing batteries in Norelco shaver"

JY From: Jim Yanik .
JY Xref: core-easynews sci.electronics.repair:340643

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


JY NiMH cells have a more complicated charge requirement than NiCd.
JY Unless you plan on designing a new charger,you should only replace
JY with NiCd cells similar to what you removed.


Riding my bike I found a cellphone flattened by traffic on the side of
the road. Its Li-ion battery seemed undamaged and it took a controlled
charge okay. I was thinking of replacing the 2 sub-C nicads in a hand
driver with it, as the Li-ion cell has a 1,000mA/hr spec on the label.
It seems impossible for such a small battery (2"x1.5x1/4"thick). There
are 3 contacts on the cell, beneath is a pcb with surface mount IC's.
One terminal is labelled TH, what is it, thermal monitor?

A*s*i*m*o*v

... That was a fascinating period of time for electronics



I don't know what the "TH" means.Possibly "THermal",maybe a thermistor for
temp monitoring. You could try measuing resistance between TH and each
other terminals,perhaps while changing the packs temp by hairdryer.

Wood Magazine recently had an article on a new drill/driver that uses Li-
Ion cells in a 28V pack with a microprocessor controller IC built into each
battery pack,it not only controls the charge,gettting the most from the
cells,but it counts charge cycles and keeps track of battery life.According
to the article,some Li-Ion formulations do not have a high discharge
current capability,that it shortens cell life.But Milwaukee says their
cells are different.Their cells are 4 volts apiece.(Is 4.8v/cell 'standard'
for Li-Ion?)

--
Jim Yanik
jyanik
at
kua.net