Functional Description - Intelligent Battery Sensor (IBS)

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 Battery voltage and current flow. The IBS also has a built in thermistor that calculates the Battery temperature. The microprocessor uses this data to calculate Battery State of Charge (SOC), Battery internal resistance, charge received, electrical demand, and time in service. This information is reported through the LIN Bus circuit to the Body Control Module (BCM). The BCM broadcasts the information to the Powertrain Control Module (PCM) over the CAN Bus.

The IBS SOC data is also used by the BCM and other modules to determine when to begin disabling certain vehicle features that draw excessive electrical loads due to a low Battery SOC. The SOC threshold for starting to disable features can vary based on vehicle and engine but is typically in the 50% to 60% range.