Disclaimer #1 - I can assemble a simple circuit from a schematic but
that is about my limit as far as skill and knowledge goes.

I've been looking at battery desulfation, and it seems to boil down to
sticking a high energy pulse of about 4 times nominal voltage (so
about 50 VDC for a 12 VDC lead acid battery) for a short duration into
the battery to break up the hard sulphation on the plates.

Every design I have looked at appears to revolve around using very
fast frequency, and very small in terms of joules per pulse, and
generally a very "delicate" approach.

I've got a bunch of coke tin sized siemens 3300 uF 350 V electrolytic
caps here, and looking at them it occured to me that they offered a
way of doing this pulse charging with far lower frequency, perhaps a
pulse a second or one pulse every ten seconds, as opposed to the kHz
rate of the desulfator circuits I have been able to find online, but
each pulse being far more energetic and therefore more likely to break
up any hard sulphate on the battery plates.

I don't know nearly enough about electronics to modify any of the
circuits I have found online (such as http://www.geocities.com/Yosemite/23..._tips/e04.html)
nor can I find anything taking this "much slower but much more
powerful pulses" approach.

What I am looking for is a schematic (with appropriate component specs
and values) that would allow me to build such a circuit and see if it
would work.

Not really worried if the circuit draws power from the battery itself
or from a charger, (with suitable isolation to prevent the high DC
voltage pulses mucking up the charger)

Can anyone help or offer any suggestions as to where I could find such
a circuit, as this orders of magnitude slower pulses and orders of
magnitude higher energy per pulse approach to desulfation doesn't
appear to have been tried, as far as I can tell.

TIA