©
2013 Magnum Energy, Inc.
Page 32
Operation
3.2.1 Battery
Charging
Magnum Energy’s MSH-RE Series is equipped with an active PFC (Power Factor Corrected) and PI
(Proportional-Integral) multi-stage battery charger. The PFC feature controls the amount of power
used to charge the batteries in order to obtain a power factor as close as possible to 1 (or unity).
This causes the battery charger to look like a resistor to the line (forces the charge current wave
shape to mirror the voltage wave shape). The PI feature allows the charger voltage and current
to change independently. These two features maximize the real power available from either the
utility or generator AC power sources, which translates into less power wasted and greater charging
capabilities than most chargers available today.
When an AC source is connected to the AC input, the inverter begins monitoring for acceptable AC
voltage. Once the inverter has accepted this AC voltage, the AC transfer relay closes and Charge
mode begins. After Charge mode begins, the DC voltage is monitored to determine the charging
stage. If the DC voltage is low (
≤
25.6 VDC), the charger begins Bulk charging. If the DC voltage
is high (>25.6 VDC), the charger will skip the Bulk and Absorb charging stages and go directly
to Float charging. The multi-stage charger can use up to
fi
ve different charging stages to help
monitor and keep the batteries healthy. The
fi
ve stages include an automatic 4-stage charging
process: Bulk, Absorb, Float, and Full Charge; and a manual Equalization (EQ) charge stage. The
automatic 4-stage charge process provides complete recharging and monitoring of the batteries
without damage due to overcharging. The EQ stage (requires a remote display to enable) is used
to stir up strati
fi
ed electrolyte and to reverse any battery plate sulfation that may have occurred.
While charging, the unit may go into charger back-off protection, which automatically reduces
the charge current to the batteries. This is caused by: 1) The internal temperature is too hot—
the charger automatically reduces the charge rate to maintain temperature; or 2) The AC input
voltage falls below 90 VAC—the charger stops charging to help stabilize the incoming AC voltage.
The Charge mode provides up to four separate charging stages: Bulk Charging, Absorb Charging,
Float Charging and Full Charge.
Bulk Charging:
This is the initial stage of charging. While bulk charging, the charger supplies the
battery with controlled constant current. The charger will remain 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 (fast
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 or 25.4 VDC or less on 24-volt models),
the charger automatically initiates another four hours in
fl
oat charge.
Info:
If the battery voltage falls to the re-bulk voltage (24.2 VDC) or lower, the unit will
begin another bulk charge.
*
These settings in the MSH-RE 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, a remote control (ME-RC, ME-ARC, or ME-RTR) may be purchased to adjust these settings.
