On 5/24/2017 6:49 AM, Jim Wilkins wrote:


Since I don't cycle my batteries daily I can afford to experiment with
slow charging from the solar panels at a few percent of the Amp-Hour
rating current. Rather than adding a current limiter which would cut
into the already minimal voltage overhead of solar panels,

There are some nifty hall-effect sensors with almost zero drop.
Used one in a solar/wind system with a shunt regulator.
Wind generators don't like being unloaded by a series regulator.

I've been
charging with simple, rugged LM317 and LM350 regulators with meters
and bumping the voltage up a little when I walk by and notice the
current has dropped. Before long the battery charges high enough that
an AGM draws only C/100 current at 15V and a flooded battery at around
14.0V, though they all are different. The current lost to electrolysis
seems to decrease, as shown by the battery drawing little more current
above 14V than at 13.6V.

I built a homebrew power supply whose current limiter adjusts from
1mA to 0.4A. I use it to restore old electrolytic capacitors at about
5mA and to desulfate free batteries that need to be hit with over 16V
to accept any current. For them the current needs a limiter to avoid
pegging the ammeter as they recover. I've been using one such free
"dead" battery in my tractor for two years.

I'd like to hear more about your desulfation successes.
High voltage didn't help. Other crazy ideas I'd read about, like
AC at various frequencies to 'ring' the plates
and shake off sulfation, etc. Got absolutely nowhere.