Backup battery

[Jens Johansson]

A general question: can I replace NiCads that are used for static RAM backup
with something better, such as Lithium cells, without modifying the charging
circuit?

(The instruments in question are polysixen BTW -- notorious for having their
backup NiCads blow up and belch all sorts of corrosive spew over the PCBs. :)

The voltages are a bit off as well -- the original design has a three-pack
of NiCads, making 3.6 volts, and the Lithiums are what, three volts each?

As an aside, does anyone know of a good, cheap source of a selection of NiMH
cells? (Why aren't these readily available in electronics stores? A
conspiracy of some sort?)

Jens. (offline) <jens at panix.com> (http://www.panix.com/~jens/)