Battery condition
The battery's condition cannot be determined based on the battery's state of charge alone. All batteries are subject to natural wear due to the natural ageing process. The chemical reactions in the battery, consisting of the charging cycles with battery charging and discharging, mean that deposits form in the battery, preventing the battery from reaching full capacity.
| Item | Explanation |
|---|---|
| 1 | Charge battery. |
| 2 | Discharge battery. |
| 3 | Ageing/deposits |
| 4 | Self-discharging. |
The enhanced intelligent battery sensor installed enables better determination of the battery condition:
- Detection of defective battery cells
- Calculation of the remaining battery capacity
Each total discharge results in a loss of battery capacity: The longer the battery remains completely discharged, the greater the loss of battery capacity. The batteries installed at BMW can withstand several short total discharges or up to two long total discharges, provided they are fully recharged with a constant charging voltage of 14.8 V after the total discharge.
If monitoring of the battery condition identifies an aged or defective battery, a fault entry is registered in the engine control unit. The fault entry can only be deleted once the battery is replaced and the battery replacement was registered.