Jim Weir had a design to bring sulphated batteries back to life.

I would guess that you don't need to do it if the battery is ok in
the first place.

I've got a 300mA 13.5V top-up thing I bought, just a constant
trickle charge, and I've actually found that I've brought a couple
of "dead" batteries back to serviceable condition by leaving that
on for a couple of weeks (car batteries).

Paulu

"Mike Rapoport" wrote in message
news
I have heard
about "pulse chargers" that reportedly reduce sulfate on the battery
plates.
Would using one of these make a meaningful difference in battery life?