Hi all :
The recent battery questions have stirred up an old project of mine : the
perfect battery charger.
I used to have a document that described the 'ideal' charging cycle for
lead acid starting batteries, but I've lost it. As I recall, it went
something like :
1) Charge at constant current (amps not to exceed amp hour rating/4) until
specified voltage. I think this number was around 14.5 volts, depending on
temperature.
2) Taper charge (current depends on voltage) until higher voltage or time
limit reached. I think this was around 15.2 volts, depending on
temperature. The goal was to equalize the voltage on all cells by
overcharging slightly.
3) Constant voltage 'float' at around 13.8 volts, again depending on
temperature.
4) If float current rises to some value, repeat charge cycle.
Does anyone have a copy of this procedure, including the temperature
compensation graphs ?
If I can find the information, is anyone interested in instructions to
build one of these ? The price for a new unit is only around $150 US, and
parts to modify a 'dumb' charger will probably be $25-50 if your
electronics junk box isn't well stocked.
Randall
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