Initial Inspection and Diagnostic Overview

61 00 ... Battery

NOTE:

Important notes and instructions for handling batteries in the dealership can be found in:
- Battery master document
- Disconnecting battery
- Battery charge
- Welding work
- External jump-starting aid

Battery care and maintenance
In low-maintenance batteries, check the electrolyte level at least once a year. If necessary, top up with distilled water up to the top marking.
The increasing number of electronic control units in the vehicle reduces the self-discharging time of the battery (even in standby mode). To maintain the battery service life and to avoid exhaustive discharging, recharge laid-up vehicles every 6 weeks at the latest (refer to battery recharging schedule here, SI 6 10 398 387). The time for self-discharging depends on vehicle type and equipment specification.

Battery test
The battery acid density can be used to measure the state of charge. However this check produces uncertainty caused by a design-related range of variation. The acid density e.g. for a charged battery is 1.28 kg/I (in the variant for hot countries the acid density is 1.23 kg/I).
Another interference factor is the acid layer immediately after filling with distilled water.
Battery wear with partially sulphated and/or heavily contaminated panels will also lead to incorrect acid density test results.