Magnum Energy MM Series Owner's Manual page 30

3.0 Operation
When an AC source (shore power or generator) is connected to an
inverter that has a battery charger, the inverter will monitor the AC
input for acceptable voltage. Once the inverter has accepted the AC
input, the AC transfer relay will close and Charge Mode will begin. Once
in Charge Mode, the DC voltage will be monitored to determine how
to charge. If the DC voltage is ≤12.9 VDC, the charger will go to bulk
charging. If the DC voltage is >12.9 VDC, the charger will skip the initial
Bulk/Absorb Charging stages and go directly to fl oat charging.
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 85 VAC – the charger reduces the
charge current to zero 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 charg-
ing, the charger supplies the battery with constant current. The charger
will remain in bulk charge until 14.6 VDC* is achieved (determined by
the Battery Type selection**).
Absorb Charging; This is the second charging stage and begins after
the bulk voltage has been reached. Absorb charging provides the bat-
teries with a constant voltage and reduces the DC charging current in
order to maintain the bulk voltage setting. The absorb charging time is
120 minutes (determined by the Battery AmpHrs selection**).
Float Charging; The third charging stage occurs at the end of the ab-
sorb charging time. While fl oat charging (also known as a maintenance
charge), the batteries are kept fully charged and ready if needed by
the inverter. In this stage, the charge voltage is reduced to 13.4 VDC*
(determined by the Battery Type selection**) which can maintain the
batteries indefi nitely.
Full Charge (Battery Saver™ mode); The fourth stage occurs after
four hours in the Float Charging stage. The Full Charge stage maintains
the batteries without overcharging, preventing 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 to 12.9 VDC, the charger will automatically initi-
ate another four hours in fl oat charge.
* These voltage settings are based on the Battery Temperature Sensor
(BTS) being disconnected, or at a temperature of 77° F (25° C). If the BTS
is installed, these voltage settings will increase if the temperature around the
BTS is below 77° F (25° C), and decrease if the temperature around the BTS
is higher than 77° F (25° C).
** The MM Series uses changeable settings (see Table 5, Inverter Default Set-
tings) that are adequate for most installations. However, if you determine that
some of your operating parameters need to be changed, the ME-RC50 remote
control can be purchased to allow changes to those settings.
24 © 2010 Magnum Energy, Inc.