Operation CHARM: Car repair manuals for everyone.

03 Battery maintenance: Checking functional state and fluid level


WM 030000 Battery maintenance: Checking functional state and fluid level

Technical values





Checking battery

Information

Before checking the battery with a battery tester, the voltage at the battery must remain static for a short time.

The described sequence must be followed to ensure this rest period is observed.

Checking functional state:
1. Park the vehicle on the lifting platform.
2. Switch off lights, switch off ignition, remove ignition key and open the luggage compartment lid.

Information

No loads (e.g. opening doors, switching on light/radio, etc.) may be activated while the vehicle is jacked up and raised on the lifting platform.

The time is long enough for the battery to rest for a few minutes.

3. Remove battery cover. -> 27121900 Removing and installing battery cover - section on "Removing" 27121900 Removing and installing battery cover

Information

Before the battery test:

If the temperature of the battery cannot be estimated, e.g. if the outside temperature and the temperature in the workshop area differ considerably, the temperature of the battery must be measured using a commercially available infrared temperature gun, for example.

4. Connect battery tester to the vehicle battery.
=> Refer to Tools and Equipment





Connecting battery tester to vehicle battery

5. The values (A), the actual battery temperature, the battery type, etc. must be input on the battery tester. Follow the operating instructions provided for the tester.
6. After a short time, the result of the test will be displayed. The functional state and the charge state, for example, will be displayed, depending on the type of tester.
7. Continue the procedure using the values displayed on the battery tester. Example in -> 270601 Checking battery with battery tester 270601 Checking battery with battery tester

Checking fluid level:

CAUTION

Danger of injury!

- The accident prevention regulations must be observed when handling battery acids.
- Wear suitable protective clothing and goggles.
- Only illuminate the inside of the battery with a pocket lamp.
- Never illuminate the inside of the battery with a naked flame.
- Do not handle a naked flame or lit cigarettes near batteries.
- Observe the disposal regulations for batteries and sulphuric acid when disposing of batteries.

8. Unscrew battery plugs.





Unscrewing battery plugs

Information

- Use a commercially available battery filling bottle.

- The correct acid level of the battery is an important factor for long and efficient operation of the battery.

- When the acid level is too low, a capacity loss (performance loss) of the battery occurs, which is caused by the cell plates drying out. If the cell plates are not surrounded by electrolyte (battery acid), it will lead to corrosion of the lead plates, plate bridges and cell connectors. The result of the corrosion is that battery functioning cannot be guaranteed. The battery will become useless.

- If the acid level is too high, damage can occur when the battery acid (sulphuric acid/water mixture) leaks out of the battery.

9. Check the fluid level of the battery. If necessary, correct the fluid level by topping up to the marking with distilled water.
10. Position battery plugs and screw on securely => Tightening torque: 1.2 Nm (1.0 ftlb.).
11. Install battery cover. -> 27121900 Removing and installing battery cover - section on "Installing" 27121900 Removing and installing battery cover