Appendix B
Battery Charging
XS Power
Intelli
CHARGER
User Guide
Appendix B
Appendix B describes battery charging in more detail.
The
Intelli
CHARGER 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
Intelli
CHARGER delivers its full-rated output
current. This constant current is delivered to the batteries until the battery voltage approaches its
absorption voltage, either 2.425V per cell or 2.375V per cell depending on battery type selected.
The bulk charge stage restores about 80% 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 read 20A, then cascade to 15A after a 10 min. time period.
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
Intelli
CHARGER exceeds the battery recharge current setting.
8
Figure B-1 Multi-stage charging profile
FAQ’s
Can I change the clamps on the charger with quick disconnects?
Yes. We recommend soldering all electrical connections where possible.
Can I run my electric water pump and cooling fan while charging?
Yes with a word of caution. There are two issues. First the charger will only provide 20A maximum
charge current. Any amperage being consumed by extra electrical loads (ie. electric water pumps,
etc.) will take away from the amperage available for battery charging. The battery charge time will
be increased. In addition, the battery charger monitors the battery voltage and time to determine
when the battery is at 100% charge. Extra electrical loads on the system will give the charger
false information and therefore will prevent the charger from properly completing stage two.
Second, some electrical items can be damaged by high voltages. Data loggers, computers, and
other items may lose data or be seriously damaged if subjected to the 19.0~20.0VDC of charging
voltage. We do not recommend retrieving this information while charging. If in doubt about a
particular component, consult with its manufacturer concerning its maximum input voltage.
CAUTION:
Data loggers, computers of all sorts, and light bulbs may be damaged by the 19.0~20.0VDC
of input voltage during charging. Do not operate these items while charging. We recommend disconnecting
the battery from the system while charging.
FAQ’s
XS Power
Intelli
CHARGER
User Guide
FAQ
9
