Theory Of Operation
WARNING: This page is about a different car, the 2017 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The Intelligent Battery Sensor (IBS) is an electrical shunt with a microprocessor that is mounted in-line with the negative Battery Cable. The IBS monitors the current flow and voltage. The IBS also has a built in thermistor that calculates the Battery temperature. The microprocessor uses this data to calculate Battery state of charge, Battery internal resistance, charge received, charge delivered, and time in service. This information is reported through a LIN BUS circuit to the Body Control Module (BCM). The BCM broadcasts the information to the Powertrain Control Module (PCM) over the CAN BUS.