Checking Gravity of Electrolyte

Battery

NOTE: To prevent contact corrosion, only approved screws, nuts, discs, etc. should be used. These elements have a special surface coating and must be stored separately.

The battery is one of the most important electrical components in the vehicle. Fault-free functioning of the battery contributes greatly to customer satisfaction. To guarantee long and efficient operation, the battery must be checked and maintained according to the versions in this chapter.

Besides the start function, the battery also has the tasks of buffer and supplier of electrical energy for the entire vehicle electrical system.

Checking gravity of electrolyte

NOTE: Only for low-maintenance batteries.

CAUTION:
- The accident prevention regulations must be observed when handling battery acids.
- Wear suitable protective clothing.
- Observe the disposal regulations for batteries when disposing of batteries and sulphuric acids.

NOTE:
- Use commercially available battery acid tester.
- The electrolyte gravity test provides information about the state of the battery in connection with the battery load test
- The temperature of the battery acid must be at least 10 degree C.

The gravity of electrolyte must be checked as follows in all battery cells (low-maintenance battery):
1. Switch ignition off and remove ignition key.
2. Unscrew all battery plugs (plugs of the battery cell).
3. Dip the acid siphon or the pipette into the battery cell and take up the battery acid.
4. Read off the gravity of electrolyte in kg/cu.dm on the scale of the battery acid tester and compare with the following table.

Battery charging condition in Spec. gravity in kg/cu.dm
normal climatic zones
discharged 1.12
half charged 1.20
well charged 1.28

Battery charging condition in tropical Spec. gravity in kg/cu.dm
climatic zone (hot countries)
discharged 1.08
half charged 1.16
well charged 1.23

The gravity of electrolyte must be at least 1.24 kg/cu.dm in normal climatic zones.
- If the gravity of electrolyte is too low, charge battery.
- After charging the battery, repeat the electrolyte gravity test.

The measuring values for the gravity of electrolyte of the individual battery cells should not deviate by more than 0.03 kg/cu.dm from each other.







Example 1: The gravity of electrolyte in cell 4 is too low.
Example 2: The gravity of electrolyte in cells 4 and 5 is too low. The specific gravity of electrolyte deviations between the battery cells is larger than 0.03 kg/cu.dm.
- If the nominal values are not achieved, replace battery.
- If the nominal values are achieved, screw in the original plug again.