© 2016 Sensata Technologies
Page 49
Operation
The Charge mode provides up to four separate charging stages: Bulk Charging, Absorb Charging,
Float Charging and Full Charge (Figure 3-7).
Bulk Charging:
This is the initial stage of charging. While bulk charging, the charger supplies the
battery with controlled constant current. The charger remains in bulk charge until the absorption
charge voltage (determined by the
Battery Type
selection
*
) is achieved. The inverter’s green LED
stays ON (solid) to indicate bulk charging.
Absorb Charging:
This is the second charging stage and begins after the absorb voltage has
been reached. Absorb charging provides the batteries with a constant voltage and reduces the DC
charging current in order to maintain the absorb voltage setting. The inverter’s green LED
fl
ashes
once every second (medium
fl
ash) to indicate absorption charging for 2 hours (determined by the
Battery AmpHrs
selection
*
), then switches to
fl
oat charging.
Float Charging:
The third charging stage occurs at the end of the absorb charging time. While
fl
oat charging, the charge voltage is reduced to the
fl
oat charge voltage (determined by the
Battery Type
selection
*
). In this stage, the batteries are kept fully charged and ready if needed by
the inverter. The inverter’s green LED
fl
ashes once every 8 seconds (slow
fl
ash) to indicate
fl
oat
charging. The Float Charging stage reduces battery gassing, minimizes watering requirements (for
fl
ooded batteries), and ensures the batteries are maintained at optimum capacity.
Full Charge (Battery Saver™ mode):
The fourth stage occurs after four hours in the Float
Charging stage. The Full Charge stage is designed to keep batteries fully charged over long periods,
and to prevent excessive loss of water in
fl
ooded batteries or drying out of GEL/AGM batteries.
In this stage, the charger is turned off and begins monitoring the battery voltage; if the battery
voltage drops low (12.7 VDC or less on 12-volt models, 25.4 VDC or less on 24-volt models, and
50.8 VDC or less on 48-volt models), the charger automatically initiates another four hours in
fl
oat charge.
Info:
If the battery voltage falls to the re-bulk voltage (12.1 VDC on 12-volt models,
24.2 VDC on 24-volt models, and 48.4 VDC on 48-volt models) or lower, the unit will
begin another bulk charge.
*
These settings in the MS Series are changeable and leave the factory with default values (see Table
3-2, Inverter/Charger Default Values). These default values are adequate for most installations, however,
if you determine that some of the values need to be changed for your particular system, a remote
control may be purchased to adjust these settings.
Figure 3-7, Automatic 4-Stage Charging Graph
Constant
Current
Reduced
Current
Reduced
Voltage
Absorb
volts
Max
Charge
Rate
Increased
Voltage
Constant
Voltage
Monitored
Voltage
No Current
Monitored
Current
Bulk
Charging
Absorb
Charging
Float
Charging
Full
Charge
Goes to Full
Charge after
4 hours in
Float Charge
Absorb
Time
Float
volts
Time
DC
Voltage
DC
Current
