Checking electrolyte level - batteries with "magic eye"

Fig 1: Locating Magic Eye

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• For batteries with "magic eye" - arrow  -, the electrolyte level can be read out via color indication. Three different color indications are possible:

Color indication	Battery charge condition
Green	Battery is sufficiently charged.
Black	No charge or charge too low.
Colorless or yellow	Critical acid level reached, battery must be recharged or replaced.