Hi Roy
On (11 Oct 97) Roy J. Tellason wrote to Jim Dunmyer...
 JD> It's also well-known amongst folks with their own home power 
 JD> system that PV panels can't be depended on to equalize the 
 JD> batteries. That is, all lead-acid batteries must be overcharged 
 JD> periodically or they will have very short lives; they might go 
 RJ> So how would I do that with these two deep cycle RV batteries I've got
 RJ> sitting here to make them last longer?
The Equalizing Charge is sometimes labelled "gassing charge" or "Boost
Charge".
It isn't usually possible with a standard ie "float" charger because these
function at about 2.35v per cell. To boost charge needs about 16- 17 volts
across a 12v battery ie 2.7v per cell. My method is to stop, when all cells 
r
gassing vigorously and uniformly. About an hour later, I top up with water
because boosting depletes the electrolyte quantity.
 RJ> Mostly I've just been maintenance charging them,  every so often,  
because
 RJ> they haven't really been loaded all that much (the RV needs some work 
:-),
 RJ> though one of them seems to be using an inordinate amount of water for
 RJ> some reason...
 RJ> I salvaged some 13.8 volt 5 amp regulators a while back,  I probably
 RJ> oughta set some of those up for float charging these puppies.
13.8 is a normal charge level, that can be left on a 12v battery 
ontinuously,
it is insufficient for equalizing.
I boost charge my auto battery once or twice a year. My wheelchair battery,
about every ten weeks.
Cheers....ALEC
... I do most of my work sitting down; that's where I shine
--- PPoint 1.92
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