Manual

Charge Controlling
975-0560-01-01 Revision B 1–5
The charge controller transitions to the float stage if either of the following two
conditions are met:
• The charge current allowed by the batteries falls below the exit current
threshold, which is equal to 2% of the programmed battery capacity (for a
500 amp-hour battery bank, this would be 10 amps), for one minute.
• The charge controller has been in absorption for the programmed maximum
absorption time limit. The default is three hours, but the time limit is
programmable from one minute to eight hours.
Float Stage
During the float stage, the voltage of the battery is held at the float voltage
setting. Full current can be provided to the loads connected to the battery during
the float stage from the PV array. When battery voltage drops below the recharge
voltage setting for one minute, a new bulk cycle is triggered.
Figure 1-2 Three-stage battery charging cycle
a
a.The charging cycle of the charge controller might differ from the curves shown above due
to the amount of solar energy available and any DC loads present on the battery system
during charge.
Float State
Absorption
State
Bulk State
Current
Time
Max Current
Limit
Voltage
Time
Absorption Voltage
Float Voltage
Max Absorb Time - dflt 3 hrs
(adjustable 1 min - 8 hrs)
Bulk/Boost
Voltage
Boost
Timer
1hr fixed
Absorption Exit Current
Threshold = 2% of
programmed AH capacity
Recharge Voltage