Magnum Energy MMS Series Owner's Manual page 41

Operation
The automatic 4-stage charging process includes:
• Bulk Charging: This is the initial stage of charging. While bulk
charging, the charger supplies the battery with constant current.
The charger remains in bulk charge until the absorption charge
voltage is achieved (14.6 VDC)*—as 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 batteries with a constant voltage and reduces the DC charging
current in order to maintain the absorb voltage setting. The absorb
charging time is 120 minutes—as determined by the Battery
AmpHrs selection**.
• Float Charging: The third charging stage occurs at the end of
the absorb 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. The Float Charging stage reduces
battery gassing, minimizes watering requirements (for fl ooded
batteries), and ensures the batteries are maintained at optimum
capacity. In this stage, the charge voltage is reduced to the fl oat
charge voltage (13.4 VDC)* —as 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 of fl oat charging. 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 low (≤12.7 VDC),
the charger will automatically initiate 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 MMS Series uses changeable settings (see Table 3-2, Inverter
Default Settings) 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.
32 © 2017 Sensata Technologies