Installation Manual

© 2014 Magnum Energy, Inc.
Page 61
Using an AGS Module: Setup
• Set Stop Gen Volts – This setting will stop the generator when the battery voltage (on Ter-
minals #3 & #4) increases to or above this setting continuously for the duration of the Stop
Volts Delay setting. To allow the battery bank to go through a full Bulk and Absorption charge,
this setting should be set to Float.
Default setting: 14.4 VDC (12v), 28.8 VDC (24v), 57.6 VDC (48v)
Range: OFF, 9.1-16.0 VDC (12v), 18.2-32.0 VDC (24v), 36.4-64.0 VDC (48v), Float
Where should I set Stop Gen Volts? Typically, when using a generator to charge batteries,
most individuals only charge the batteries to 80-85% to compromise between minimizing fuel
usage and maximizing battery life. This is done by having the generator start on low battery volt-
age, and then stop at a higher voltage (i.e., the Stop Gen Volts setting). When deciding where
to set the Stop Gen Volts setting, it must be lower than the inverter’s Absorb Volts setting (de-
termined by the SETUP: 03C Battery Type/Custom setting menu). Otherwise, the charger will
enter Absorption charge mode—which is required to maintain the batteries at a constant voltage
level—and the battery voltage will not reach the Stop Gen Volts setting, which will cause the gen-
erator to run until it is out of fuel or until it reaches the SETUP: 04F Max Gen Run Time setting.
Therefore, after reading this some will think that they should just set the Stop Gen Volts setting
slightly lower than the absorption level to ensure the charger always reaches the Stop Gen Volts
setting before it goes into the Absorption charge mode. However, temperature changes can affect
the Absorb Volts setting¹ and may require you to readjust the Stop Gen Volts setting seasonally.
If you are in a normally cold climate (<32°F), the actual absorb charge voltage will increase. So,
the Stop Gen Volts setting should be set well above the Absorb Volts setting (~.5V above for
12-volt systems). If you are normally in a hot climate (>95°F), the actual absorb charge voltage
will decrease. In that case, the Stop Gen Volts setting should be set well below the Absorb Volts
setting (~.5V below for 12-volt systems).
A simpler way to charge the batteries to 80-85% and to automatically allow a temperature-
compensated charge to the batteries (no seasonal adjustment required) is accomplished using
the settings below:
• Set the Stop Gen Volts setting to Float
• Set the Absorb Volts setting (SETUP: 03C Battery Type/Custom setting) to the voltage
level at which you want the generator to turn off (normally ~ 14.5 volts for fl ooded
batteries in a 12-volt system)
• Set the Absorb Done Time setting (SETUP: 03D Absorb Done Time) to 0.1 hours
Using these settings, when the batteries reach a low voltage level the generator turns on (per the
Start Gen Volts setting) and charges the battery to the temperature-compensated Absorb Volts
setting. After reaching the absorption voltage level, the inverter/charger goes into Absorption
charge mode and is there for only six minutes (0.1 hours) before it goes to Float charge mode.
Once the inverter/charger enters Float charge mode, the AGS autostops the generator.
Info: Battery life will be reduced if the batteries are regularly charged to only 80-85%.
It is highly recommended to charge the batteries to 100% as often as possible (~ once
a week, or every other discharge cycle) in order to avoid sulfation of the battery plates.
Using the SETUP: 03D Absorb Done Time menu, the absorption charge time can easily
be changed to a longer duration to increase the batteries’ state of charge.
Note: If a ME-BMK (battery monitor) is installed in the system, refer to the SETUP: 04K
Gen 100% SOC Start Days menu, which can be used to autostart the generator and to
periodically charge the battery to 100%.
• Set Stop Volts Delay – This setting determines the amount of time the battery voltage must
be above the Stop Gen Volts setting before the AGS autostops the generator.
Default setting: 120 Sec
Range: 0-127 Sec, 1-127 Min (1-sec increments up to 127 sec, then 1-min increments)
Note¹: When the inverter’s BTS is connected, the actual absorb charge voltage will increase or
decrease to ensure correct charging as the battery temperature changes.