08-11-2017, 07:15 AM
In many applications an occasional charge at a few amps briefly to 7.7 or more volts or whatever the battery peaked at, was desirable to ensure all battery brought into operation. On the other hand, many batteries in regular varied use experienced full charge by one means or another.
If anything could, a prolonged slow charge was reckoned to remedy sulphated batteries, but often needed a high voltage to start.
Most commercial chargers are arranged to be reasonably foolproof so max voltage is limited. A simple old style charger with generous output can be used with resistance wire, voltmeter etc to cover all situations but has to be closely monitored.
The advent of low and no maintenance batteries with cadmium and different characteristics has greatly complicated matters and made much traditional practice and recommended voltages inappropriate. It is now difficult to find authoritative info as was readily available from books in the past.
If anything could, a prolonged slow charge was reckoned to remedy sulphated batteries, but often needed a high voltage to start.
Most commercial chargers are arranged to be reasonably foolproof so max voltage is limited. A simple old style charger with generous output can be used with resistance wire, voltmeter etc to cover all situations but has to be closely monitored.
The advent of low and no maintenance batteries with cadmium and different characteristics has greatly complicated matters and made much traditional practice and recommended voltages inappropriate. It is now difficult to find authoritative info as was readily available from books in the past.