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Battery load test > < No load voltage measurement

Golf Mk3

Electrical system
Battery
Checking specific gravity of all cells
Warning!
When using sulphuric acid it is absolutely necessary that the accident prevention procedures are observed. Suitable protective clothing must be worn.

When disposing batteries it is absolutely necessary that the disposal procedures for batteries and sulphuric acid are observed.
Ensure that the following notes are observed otherwise a correct check cannot be guaranteed.
 
N27-0094

The electrolyte specific gravity test in conjunction with the battery load test provides specific information of the battery condition.

Special tools, testers and auxiliary items

  • ◆ →      Commercially available hydrometer
  • ◆ Cleaning cloths

Notes:

  • ◆ A battery temperature of at least 10 °C is required when carrying out specific gravity tests.
  • ◆ The electrolyte density can be checked immediately after charging battery.
  • ‒ Remove all battery plugs (battery cell sealing plugs).
 
N27-0081
  • ‒ → Immerse end of hydrometer in a cell and extract sufficient electrolyte so that float swims free in the electrolyte. This sequence is to be repeated until all cells have been tested.
  • ‒ The greater the electrolyte density (specific density) in kg/dm3 of the extracted electrolyte the more the float floats free. The electrolyte density in specific density kg/dm3 can be read off the scale on the float.

Deviations in electrolyte density

Notes:

  • ◆ The maximum permissible differences (deviations in electrolyte density) between the cells must not be greater than/same as 0.04 kg/dm3.
  • ◆ The electrolyte density must be at least 1.24kg/dm3.

Example of unacceptable deviations in specific gravity:

Specific gravity deviations in kg/dm3per cell

Example 1:

1.24

1.25

1.25

1.10

1.24

1.25

Example 2:

1.26

1.26

1.25

1.14

1.18

1.24

Deviations in electrolyte density in
Example 1, cell 4 (1.10 kg/dm3), as well as
Example 2, cell 4 (1.14 kg/dm3 ) and cell 5 (1.18 kg/dm3 ) are not permitted. The batteries shown in the examples are no longer usable and must be disposed of.

The following values must be attained:
 
N27-0081

Charge condition in normal climatic zones

Specific
densities in kg/dm3

Discharged

1.15

Half charged

1.22

Well charged

1.28
Warning!
It is essential that genuine and proper battery sealing plugs be used to ensure that the differing battery cover systems are sealed correctly. Only use genuine sealing plugs of same construction if lost or damaged.


The plugs must be equipped with an O-ring seal.

Battery load test > < No load voltage measurement