Volkswagen Golf Service & Repair Manual: Current draw test

WARNING It is not permissible to test or charge batteries whose magic eye shows light yellow. Do not slave/jump start the vehicle!

Danger of explosion when checking and charging or slave/jump starting.

These batteries must be renewed.

Note Ensure that the correct charging mode is set on the charger so that the current draw test is not falsified.

VAS 5095 A → Chapter

VAS 5900 → Chapter

VAS 5903 → Chapter

To quickly ascertain the state of discharged batteries, the battery current draw test whilst charging helps to determine whether the battery must be replaced or fully recharged.

Note For battery tester with printer -VAS 6161-, the current draw test must always be performed when the test result “Perform current draw test” appears on the display.

The current draw test should always be carried out if

The result of the test with battery tester with printer -VAS 5097A- gave the following results:

1 -	Starting capability sufficient

2 -	Starting capability poor

3 -	Starting capability very poor

4 -	Cannot be tested – charge battery and repeat test.

and when the tester will not switch on (no LED, no printout)

or

The result of the test with battery tester with printer -VAS 6161- gave the following result:

1 -	Perform current draw test

Performing a current draw test whilst charging a battery will quickly establish whether a partly or fully discharged battery → Chapter can be recharged to return it to a serviceable condition.

Test requirements:

When charging the battery, its temperature must be at least ≥ +10 °C.

The charger must be capable of outputting a charge current of at least 30 A, as for example with VAS 5095A, VAS 5900, VAS 5903 The battery's current draw must be measured with a current pick-up clamp, e.g. VAS 5051B/7, when charging with battery charger -VAS 5095A-. Battery charger -VAS 5900- and battery charger -VAS 5903- display the current draw on the unit. Battery charger -VAS 5900- performs the current draw test automatically with menu guidance.

Connect battery to battery charger and start charging sequence.
Measure charge current of battery after 5 minutes.

Test result:

If the current draw A is higher than 10% of the nominal capacity (e.g. > 6.1 A for a 61 Ah battery), fully charge battery and test again. Note For Eos with two 6V absorbent glass mat batteries, the charge current must only be 5% higher than the nominal capacity of the battery. Example for Eos: the 50 Ah battery must have a charge current higher than 2.5 A after 5 minutes of starting the charging sequence.

Fully charge the battery when the charge current is higher than 10% of the nominal capacity (observe exception for Eos in above note).
Perform battery test after allowing battery to rest for two hours → Chapter.

If the charge current, in amperes, lies below 10% of the nominal capacity after 5 minutes of starting the charging sequence (5% for the 2 x 6 volt batteries in the Eos) (example for 50 Ah battery < 5A), renew battery. For warranty and goodwill cases, please complete the battery test sheet.

Current draw test