Intelligent battery sensor
The intelligent battery sensor is secured to the negative battery terminal and connected with the engine control unit via LIN bus. The intelligent battery sensor is an extremely important component for energy management in the vehicle network. It is a mechatronics component for monitoring the battery condition. The following measured variables are registered:
- Terminal voltage
- Charge current and discharge current
- Temperature of the battery terminal.
Upstream processing of especially time-critical measured variables is carried out by the integrated microprocessor. The results are then transferred to the engine control unit via the LIN bus.
The following graphic shows the negative battery terminal using the example of F10.
| Item | Explanation |
|---|---|
| 1 | Intelligent battery sensor |
| 2 | 1-pin plug connection |
| 3 | two-pin plug connection |
| 4 | Ground cable |
| 5 | Negative battery terminal |
The software in the engine control unit controls the communication with the intelligent battery sensor. Calculation of the battery condition (SOH = State of Health) as well as calculation of the state of charge (SOC = State of Charge) is carried out in the engine control unit.
In the time between engine OFF and the switch-off of the Digital Motor Electronics main relay, the intelligent battery sensor receives the following information from the engine control unit:
- Maximum removable charge for a reliable engine start.
After switch-off of the DME main relay, the intelligent battery sensor continuously checks the state of charge and standby current consumption.