> When a battery is a long time on preset float voltage a cell [or cells]
 > behaves as the runt in the family, and its terminal voltage becomes 
 > a little
 > suppressed. This automatically causes the charger to pump more amps 
 > and the healthy cells in the same battery oblige by raising v a bit, but 
 > still ahead of the runt, and the charger current self limits to a small 
 > amps value.
 > 
 > In time a survey of that battery with a voltmeter, may show cell 
 > voltages like:
 > 
 > 2.15  2.45  2.45  2.45  2.40  2.60.  Total, 14.50v
Exactly what that KW Battery book explained.
I've found that my big RV/trolling batteries on the UPSs here don't seem to 
hold up at all well. IE: a couple of years and they're done. It finally 
dawned on me the the charger in the UPS is voltage limited to a low enough 
value that the batteries will have to be equalized now and then.
I've gotten into the habit of load-testing the batteries, then charging them 
at 5 amps for 5 hours, once per month or so. There's a log sheet hanging on 
the wall for recording the CCA values indicated by the tester alongside the 
date.
Interestingly enough, the gel-cell type batteries that are OEM in those UPSs 
don't seem to need this treatment to hold up for several years. They'll 
usually go 3-5 years without replacment.
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