Installation Manual

Using an AGS Module: Setup
© 2017 Sensata Technologies
Page 83
Note¹: When the inverter’s BTS is connected, the actual absorb charge voltage increases or
decreases to ensure correct charging as the battery temperature changes.
• Set Gen Run DC Volts (Stop Volts) – This setting will stop the generator when the battery
voltage (on Terminals #3 & #4 of the AGS) increases to or above this setting continuously
for the duration of the Set VDC Delay Times (Stop Delay) setting. To allow the battery bank
to go through a full Bulk and Absorption charge, this setting should be set to Float (Silent).
Default settings: Stop Volts = 14.4 VDC (12v), 28.8 VDC (24v), 57.6 VDC (48v)
Ranges: 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 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 voltage,
and then stop at a higher voltage (i.e., the Stop Volts setting). When deciding where to set the
Stop Volts setting, it must be lower than the inverter’s Absorb Voltage setting (determined by the
SETUP: 03C Battery Type 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 Volts setting, which will cause the generator 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 Volts setting slightly
lower than the absorption level to ensure the charger always reaches the Stop Volts setting
before it goes into the Absorption Charge mode. However, temperature changes can affect the
absorb voltage setting¹ and may require you to readjust the Stop Volts setting seasonally. If you
are in a normally cold climate (<32°F/0°C), the actual absorb charge voltage will increase. So,
the Stop Volts setting should be set well above the absorb voltage setting (~.5V above for 12-volt
systems). If you are normally in a hot climate (>95°F/35°C), the actual absorb charge voltage
will decrease. In that case, the Stop Volts setting should be set well below the absorb voltage
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 Stop Volts to Float
• Set Absorb Volts (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 Absorb Done Time (SETUP: 03D Absorb Done Time) to 0.1 hours (lowest setting)
Using these settings, when the batteries reach a low voltage level the generator turns on (per
the Start Volts setting) and charges the battery to the temperature-compensated Absorb Voltage
setting. After reaching the absorption voltage level, the inverter/charger goes into Absorption
Charge mode and is there for only 6 minutes (0.1 hours) before it goes to Float Charge mode.
Once the inverter/charger enters Float Charge mode, the AGS will autostop the generator.
Info: Battery life will be reduced if the batteries are regularly only charged to 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/04J
Gen 100% menu, which can be used to autostart the generator and to periodically charge
the battery to 100%.
• Set VDC Delay Times (Stop Delay) – This setting determines the amount of time the battery
voltage must be above the Stop Volts setting continuously before the AGS will autostop the
generator.
Default setting: Stop Delay = 120secs
Range: 0-127 Seconds, then 1-127 Minutes