Electrolyte level - battery with charge indicator (magic eye), checking
NOTE:
- Audi TT equipped with the 3.2L V6 engine are equipped with an Absorbed Glass Mat (AGM) battery located in the left rear luggage compartment in the spare tire/wheel well.
- Unlike conventional lead-acid batteries, AGM batteries are completely sealed and use a fiberglass mat construction which completely absorbs the electrolyte. As a result, no excess electrolyte is present, and it is not possible to check the electrolyte level or otherwise service the electrolyte.
- If it is determined that an AGM battery is malfunctioning, replacement is necessary.
- The following procedures apply only to batteries with removable cell caps.
WARNING:
DO NOT attempt to open an AGM battery!
Charge indicator -arrow- displays electrolyte level and charge condition.
NOTE:
- As the charge indicator is located in a single cell, the electrolyte indication is only valid for that cell.
- If the charge indicator on batteries in excess of 5 years old are colorless, DO NOT attempt to top up electrolyte level. Battery must be replaced.
- Air bubbles that occur normally during battery charging (even during vehicle operation) may adversely affect charge indicator reading. To obtain an accurate reading, gently tap the charge indicator with a screwdriver handle or rock the vehicle in order to displace any possible air bubbles that have formed.
Charge indicator readings
- Green = sufficient charge (and electrolyte level) OK
- Black = no charge or insufficient charge. Refer to Battery, charging .
- Colorless or yellow = critically low electrolyte level. Top up with distilled water immediately. Refer to Electrolyte level - battery with cell caps, checking .