On Wed, 28 Sep 2005 08:02:35 +1000, John Henderson
wrote:

"ASAAR" wrote:

But adding negative pulses (slightly discharging between
positive charging pulses) supposedly leaves the chemical
structure of the battery in a better state. i.e., the
batteries retain their fullest capacity for a greater number
of charge cycles.

As I understand it, PCR (periodic current reversal) has a
beneficial effect on the physical structure of a metallic
cathode as it's formed, rather than a chemical effect.

In fact, I believe PCR is required in electroplating, otherwise
the plated material is too spongy to be useful. In a battery,
this can mean dendrite formation.

My own electroplating experiments (without PCR) when I was
young produced very soft deposits.

Well in a previous life I used to work in Nikkel electroplating but we
always used "straight" DC .. Our biggest enemy in deposits quality was
actually copper :-) which made the deposits brittle. But times may
have changed :-)
FWIW