> I just completed ruining two 12 volt hi crank amp batteries, evidently by
> keeping them charged ???
>
> I had two 1100 cca batteries that I kept on trickle charge as backups for
> my generator and occasional jump start on a car or tractor in the
> neighborhood. The consensus is that just keeping 1-3 amps on the
> batteries doesn't 'exercise' them and the plates will 'sulfate'
> ??? .. a
> neighbor suggested using a pulse type charger.. my question...
Well, I strongly disagree with that consensus! When lead-acid batteries are
charged past full charge (as your trickle charger is doing), the water in
the electrolyte disassociates into hydrogen and oxygen, which get blown out
the vents. Over a period of time, you simply boil away all the electrolyte,
and the too-strong acid left behind does things like eat plate separators.
Sulfation is normally associated with lead-acid batteries that have been
left partially or fully discharged. The solution to your problem is to get
a "battery maintainer" type charger that senses the battery voltage and only
applies charge current when needed.
> can someone explain what the process is ?? is this just
> unfiltered dc ??
> or is there a occasional surge voltage that burns off the sulfates ???
There is an occasional, very short, burst of voltage that in theory breaks
up any sulfate formation.
> I know these units can be bought but can they be home built ??
Yes.
> anyone got a schematic ??
Some work with Google turned up :
http://shaka.com/~kalepa/desulf.htm
http://www.flex.com/~kalepa/faq.htm
http://www.homepower.com/files/desulfator.pdf
Randall
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