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ABS3 Owner’s Manual
Document: OM-215 Version Code: B
Date: Jan 28, 2021 Date: Aug 9, 2021
InPower LLC
8311 Green Meadows Drive
Lewis Center, Ohio 43035 USA
740-548-0965
www.InPowerLLC.com
© Copyright 2021 InPower LLC
2.0 Operation
In a system with the ABS3, the auxiliary battery is charged from the chassis battery and alternator, while the
chassis battery is protected from a total discharge, and therefore is available for starting the vehicle. As the
ABS3 is bidirectional, a charging device (such as a battery charger or gen-set connected to the auxiliary
battery) can also supply charging current to the chassis battery through the ABS3 while maintaining total
discharge isolation.
The ABS3 switch accomplishes it’s tasks through the constant monitoring of voltage and current by it’s
microprocessor controller. The proper time to transfer power in either direction between the chassis battery
and the auxiliary battery is based on a proprietary algorithm that utilizes both battery voltage and current
measurements. A “boost start” feature is provided that will allow the auxiliary battery to supply current to the
chassis battery to aid engine starting.
Since this is an intelligent switch monitoring voltage, current, and temperature, it is possible to accommodate
a wide variety of customer needs for operation, with programmable times, voltage and current settings. For
custom requirements, please contact InPower LLC directly for your needs.
LED shows whether the ABS3 is ON (LED ON) or OFF (LED OFF).
2.1 Normal Operation
Chassis
Battery
Alternator
Engine Compartment
InPower LLC
ABS3 Electronic
Auxiliary Battery Switch
Fuse *
Chassis
Loads
* SAE required wiring safety fuse. Not
supplied with ABS switch. SAE requires
within 18 inches of Battery.
Auxiliary
Loads
Aux
Battery
On
System Diagram with Charger
Boost Mode
12V
INPUT
BAT 1 BAT 2
12V 200 AMP Auxiliary Battery Switch
LED
GND
www.InPowerLLC.com Lot Code
InPOWER
the systems people
ABS3-200A
7.0-18Vdc
INPUT
8.0-18Vdc
Patented
www.InPowerLLC.com/Patents
Battery
Charger
13.2V
14.2A
Fuse *
Bi-Directional Mode
Conventional Current
Flow Depicted
Electronic
Switch
For normal operation, it is assumed that the engine is running and the alternator is supplying power to the
charge the chassis battery. When the chassis battery voltage (BAT 1) rises above 13.5 volts for 10 seconds,
the ABS3 closes and passes current to the BAT 2 side. This connects the two batteries to now charge the
auxiliary battery and power auxiliary loads.
Bidirectional Note: In the gure above, either the Alternator or the Battery Charger can charge the batteries
based on the charge requirement of either of the two batteries in the system. For the Battery Charger source,
the Auxiliary Battery becomes the Primary and the Chassis Battery becomes the Secondary Battery which the
ABS3 turns on to charge.
Over-current fault handling: If the ABS3 rated current is exceeded, the ABS3 will turn off after 1 second. If
no faults exist, the ABS3 will turn back on after 30 seconds
Automatic Operation:
• Module will automatically turn ON when battery voltage on either BAT 1 or BAT 2 is greater than
13.5Vdc for greater than 10 seconds.
• Module will automatically turn OFF when the battery voltages on BAT 1 and BAT 2 are less than
12.80Vdc for greater than 10 seconds.
