Battery Monitoring Sensor
The battery monitoring sensor is on the battery's negative pole and communicates with the Engine control module (ECM) via serial communication (LIN).
The sensor continuously measures and calculates:
- The battery's voltage.
- The current into and out of the battery.
- The temperature at the negative terminal. The value is used to calculate the battery's internal temperature with the aim of regulating the correct charge voltage and calculate the correct battery capacity.
- The voltage and current that the battery has during engine start-up (the starter motor running). The values are used to calculate the battery's internal resistance. The battery's internal resistance is used to determine the battery's capacity to supply high current during, for example, engine start-up.
- The vehicle's standby current consumption.
- The battery's standby current when the vehicle is in sleep mode. The value is used to calculate the battery's SoC.
The measurements are taken to ensure the status of the battery.
This information is sent to the Engine control module (ECM), which then calculates how the alternator is to be regulated to charge the battery optimally and determine under what operating conditions it is most economical to charge the battery.
There are a number of values to read out from the battery monitoring sensor via the Engine control module (ECM).
The battery monitoring sensor is connected to the battery positive pole. The connection is needed to measure the sensor's processor and its calculations.
The battery monitoring sensor consists internally of:
- Shunt resistance to determine the current.
- Processor with LIN communication.
The engine control module (ECM) can diagnose the battery monitoring sensor.