This function is used to check the battery charge status and history. The battery charging status is determined, while driving and when the vehicle is stationary, by the APM system (Advanced Power Management).
During driving:
The battery charge and discharge current are balanced.
The current path at engine start is calculated to determine the battery status.
The data information is transferred by the intelligent battery sensor (IBS) via the LIN bus to the engine control unit (DME, DDE, EDME).
When stationary vehicle, the quiescent current measurement is performed cyclically to identify energy loss. The measured values are stored in the memory of the intelligent battery sensor and is transferred to the engine control unit at the next engine start.
The engine control unit stores the following values for the battery charge status history:
Battery charge status for the last five days.
Histogram of the state of charge with the time areas 0-40%, 40-55%, 55-70%, 70-85% and 85-100%. The state of charge histograms are reset at a registration of battery replacement or programming of the engine control unit.
Test conditions:
Ignition on, engine off.
No faults in the system.
Procedure:
Start the function.
The following data is read out from the intelligent battery sensor:
Current registered battery capacity.
Odometer reading at the last battery change.
Current odometer reading.
For further information, press the "Yes" button, to display the following data: