NiCd Pack Discharger

[The Lightning Stalker]

NiCd don't like to sit around. It is
recommended to cycle them at least once a
month. Otherwise crystals can form inside
and they will go bad. They are still used
in some tools and other thigs. NiMH are
slightly better about crystal formation,
but do not deliver the current or the
discharge cycles.

This is just a simple little circuit to
discharge the pack to a predetermined
voltage. It is recommended to discharge to
0.4V/cell, or pack voltage divided by 3.
In my case, pack voltage was 14.4V, so the
final voltage is supposed to be 4.8V (12
cells).

Set the output of the LM317L on pin 3 of
the LM741 to the final voltage using the
pot. Beware the 30 turn pots from China.
I had one go bad on me the first time I
used it. Once they reach the presticion,
it is best to leave them alone! Good thing
they come in bags of ten :yh:

The best lamp to use depends on the pack.
A drill pack like this can run a spot light
or car marker lights and possibly
headlights. For high voltage packs, put a
couple lamps in series.

 

[joeyss]

Yeah i remember a NASA page about this.

i'll post it if i can find it.