XS Power IntelliSUPPLY PSC15 User Manual - page 17
Appendix B
Battery Charging
XS Power IntelliSUPPLY User Guide
Appendix B
Appendix B describes battery charging in more detail.
The IntelliSUPPLY charges batteries in a sequence known as multi-stage charging. The charging
voltage delivered to the battery depends on the battery’s depth of discharge.
The three automatic stages are:
• Stage One - Bulk
• Stage Two - Absorption/Equalization
• Stage Three - Float
Bulk Charge
In the first stage, known as “bulk” charging, the IntelliSUPPLY delivers its full-rated output
current. This constant current is delivered to the batteries until the battery voltage approaches
its absorption voltage, either 2.5V per cell or 2.375V per cell depending on battery type selected.
The bulk charge stage restores about 75% of the battery’s charge and this stage completes very
quickly unless the battery is deeply discharged. During this stage the charge rate current on the
ammeter should close to the charge rate selected on the front panel switch.
Absorption/equalize Charge
During the second stage, known as “absorption” charging, the charging voltage is held constant
near the gassing voltage, and the charging current is allowed to diminish as the battery comes
up to 100% charge. Complex algorithms considering the time, voltage level, and charging current
determine when the charger exits this mode and goes to stage three, float charging. The length
of time of this mode depends on the battery and is not fixed.
Float Charge
The third stage, called “Float” charging is a maintenance mode in which the output voltage of
the charger is reduced to a lower level, typically about 2.26 V per cell to maintain the battery’s
charge without losing electrolyte through gassing. In the float mode, the charger will initiate a
new charge cycle if:
• AC power is disconnected and reconnected
• The current demand on the IntelliSUPPLY exceeds the battery recharge current setting.
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