OT: Battery Charger DIY...

[J.G. Wong]

Hi,

    Unfortunately I am away from my bases on business but I was involved
in some Nicad research that is related to your charging problem so I can
tell you a little but no specifics because my stuff isn't handy.

    The organization that I work for has 500,000+ nicads out in the
field with an amazing failure rate.  We discovered two things: First
never completely discharge any rechargeable battery, running it to zero
will damage i.e. begin contamination processes that will eventually
destroy the battery. Secondly, there is a semiconductor solution to the
charge/ overcharge , time charge problem.

    There is a chip controller  that goes into a charging circuit, what
it does is allow you to dump current as quickly as you are comfortable
into a single cell,  it will sense if the cell is properly polarized,
then it will charge it to the proper voltage wait for the top spike
(charge  peak) then switch to trickle mode.  I have several of these at
work and they are amazing. I can evaluate and charge cells that took a
day in the past.  The downside to them is one controller to a cell (or
pack)..  The chargers work on nicad and gel cells.  The controller chip
cost is about $37 (us) a charger that goes up to 25 volt cells is about
$250.

Batteries can come in handy when recording, no AC no hum.

 If you are interested I'll dig up some detalis when I get back to town.

Fiveman