Checking electrolyte level (batteries with no magic eye (condition indicator)) and correcting if necessary — VW

Special tools, testers, measuring instruments and auxiliary items required

VAS 5045 Battery filling bottle

Test prerequisites =>visual check on page
27-3
.

A correct electrolyte level in the battery is an important factor in ensuring a long battery service life.

An insufficient electrolyte level allows the battery plates to dry which results in a loss of capacity (reduced output) of the battery. If the cell plates are not covered by electrolyte (battery acid) the plates, the plate bridges and the cell connections will corrode. This corrosion ensures the battery function can no longer be guaranteed. The battery is unusable.

If the electrolyte level is too high, damage will be caused outside the battery by leaking battery acid (sulphuric acid/water mixture) e.g. components in engine compartment.

Checking electrolyte level using the "min. and max. marks":

For batteries with a recognisable min. and max. marks on the outside of battery housing, a visual check of the electrolyte level is all that is required.

Switch off ignition.

Check electrolyte level visually.

The electrolyte level is OK. when the fluid level is between the minimum (min.) and maximum (max.) markings.

If the electrolyte level is not OK., correct electrolyte level as described on page
27-19
.

Checking electrolyte level without the "min. and max. marks":

Special tools, testers, measuring instruments and auxiliary items required

VAS 5038 A Battery operated light

If no min. and max. markings are visible on the battery housing, or the electrolyte level is not visible (opaque housing) the sealing plugs must be removed.

Warning!
When working with sulphuric acid it is absolutely necessary to adhere to the accident prevention procedures.
Suitable clothing must be worn.
Use only an electric torch to illuminate the inside of the battery.
Never illuminate the inside of the battery housing with an open flame.
Never work with an open flame or burning cigarette in the vicinity of a battery.
Ensure the legislation concerning the disposal of batteries and sulphuric acid is observed when disposing batteries.
Then you can check the electrolyte level by looking inside the battery.

Illuminate the inside of the battery housing with, for example, the battery operated light VAS 5038 A.
Check electrolyte level visually.

The electrolyte level is OK. when the fluid level is the same height as the plastic peg or the cell plates are covered.

The plastic plate equates to the max. marking for the electrolyte level.

If the electrolyte level is not OK., correct level as follows:

Correcting electrolyte level:

Special tools, testers, measuring instruments and auxiliary items required

VAS 5038 A Battery operated light
VAS 5045 Battery filling bottle

Commercially available hydrometer

If the electrolyte level is too low, fill only with distilled water up to the max. marking using the battery filling bottle VAS 5045.
If the electrolyte level is too high, use a commercially available hydrometer to extract excessive electrolyte until the fluid level is the same level as the inner plastic peg level marking.
After completion of correction procedure, fit genuine/original sealing plugs only to the battery cells again.

Notes:

The construction of the filler neck on filling bottle VAS 5045 prevents an overfilling of the battery cells and therefore stops electrolyte leaking out. When the max. level is reached the flow of distilled water into the battery cell is interrupted.
Use distilled water only, this prevents contamination of the battery electrolyte which leads increased self-discharge.

It is absolutely necessary to use genuine/original sealing plugs in the battery screwed openings to guarantee the battery is sealed correctly.

Use genuine/original sealing plugs of same construction if lost or damaged.

The sealing plugs must be fitted with an O-ring.