Operation
60
Stage 1—Bulk Charge
During the bulk charge stage most of the energy that has been
consumed during discharge is returned to the battery bank.
The charger enters this phase as soon as you turn the charger
on, i.e., as soon as you connect AC power to the appropriate
AC input. The charger delivers full rated current to the battery
bank, until the acceptance charge voltage limit is reached. This
results in a relatively rapid recharge.
Bulk Charging Wet Cell Batteries
Generally, a wet cell battery bank should not be charged at a
rate that exceeds 25% of its capacity.
When you completely charge a wet cell deep-cycle battery,
you must raise the battery voltage beyond the point where the
battery begins to bubble and give off gas. This is called the
gassing point. If charging stops short of this point, sulfate is
left on the plates and the battery begins to deteriorate. The
gassing point will vary with battery temperature. At 77° F, the
gassing point of a 12-volt battery is about 14.0 volts.
Bulk Charging Gel Cell and AGM Batteries
Gel cell and AGM batteries can accept a higher current rate of
charge (amps). Consult the manufacturer for specifications.
Do not charge AGM and Gel cell batteries to their gassing
point. The high voltage charging which gasses these batteries
is harmful to them. They typically require a lower bulk charge
voltage and a higher float voltage than wet cell batteries.
