Battery, Starter, Generator, Cruise Control

Support Mode with Battery Charger -VAS5900

~3min read

General Information

The support mode provides the vehicle electrical system with voltage when the battery is removed or disconnected. For more information. Refer to Battery Charger -VAS5900- Operating Instructions.

The support mode is used for the following situations

Vehicle electrical system support mode with the battery not installed

Maintaining the voltage when the battery is being replaced

Testing without the battery

WARNING Risk of injury. Follow all Warnings and Safety Precautions. Refer to → Chapter „Warnings and Safety Precautions“.
WARNING Batteries that have a light yellow visual indicator do not have to be tested or charged. Jump starting must not be used!

There is a risk of explosion during testing, charging or jump starting.

These batteries must be replaced.

  • Turn off the ignition and all electrical consumers.
Caution The polarity protection of the charger clamps is not active in the operation mode “charging severely discharged batteries/Support mode”. Connect the charger clamps to the battery terminals correctly according to polarity!

It can result in sparks due to short circuit.

This constitutes an explosion risk.

Make sure the charger clamps are secure.

Do not touch START/STOP when battery cables are incorrectly connected! The charger can be damaged.
  • Remove the battery.
  • Plug in the electrical system connector of the charger. The last selected operation mode is shown on the display. Refer to → Chapter „Battery Charger -VAS5900- Device Description“.
Caution Whenever the battery is removed, be careful to prevent contact between the connected charge clamp on the positive terminal and the body ground. Likewise prevent contact between the battery terminals.
  • Connect the red charging clamp “+” to the vehicle positive terminal.
Note In the case of vehicles with a start/stop function and an installed Battery Monitoring Control Module -J367-, the black charging clamp (-) must be connected to the body ground. The start/stop system will malfunction if it is connected to the negative terminal on the battery.
  • Connect the black charging clamp “+” to the vehicle negative terminal.
  • Press START/STOP for approximately 5 seconds. The menu item “Charging severely discharged batteries/Support mode” is activated.
  • Press the corresponding button “Up”↑ or “Down”↓, to set the respective battery voltage (6 V, 12 V or 24 V).
Note If no button is touched within five seconds, the battery charger will return to the main menu (operating mode selection).
  • Confirm the selected battery voltage by pressing START/STOP.

Then the inquiry about the correct polarity of the charging clamps is made.

  • Verify that the charger clamps are connected to the correct polarity.
  • Confirm that the charger clamps are connected to the correct polarity by pressing START/STOP.

The battery charger starts the battery support mode.

End Battery Support Mode

  • Press START/STOP.
  • Remove the black charging clamp “-” of the charger from the negative battery terminal of the vehicle.
  • Remove the red charging clamp “+” of the charger from the positive battery terminal of the vehicle.
  • Pull out the electrical system connector of the charger.

Test yourself

A quick Volkswagen Polo quiz: every answer comes with an explanation and a link to the manual page.