On Sun, 08 Jan 2006 05:54:48 -0800, Andy Evans burbled:

I'm looking for a build-it-yourself option for a lead acid battery
charger. Must be able to charge 6v batteries, and preferably 4v and 2v as
well (when I find some - anyone know suppliers in UK???). Features I'd
like a
a) Switchable between one pair of batteries in use and another on charge,
so I have permanent charge
b) Overcharge protection so at the end of charging the batteries float c)
Able to charge a couple of 6v 12Ah batteries in ideally approx. 4 hours


Have a look for a data sheet on LM138/LM338 voltage regulator. There are a
couple of circuits for battery chargers on there.

http://www.national.com/pf/LM/LM338.html

--
Mick
(no M$ software on here... :-) )
Web: http://www.nascom.info
Web: http://projectedsound.tk