1. Open the hood of the vehicle.
2. Locate the black plastic cover on the right (driver's) side of the engine bay.
3. Remove the cover by undoing the two plastic clips that secure it.
4. The battery will be located beneath the cover.
For a W210 E-Class Sedan/Wagon:
1. Open the hood of the vehicle.
2. Locate the black plastic cover on the rear left side of the engine bay.
3. Unlatch the two spring clips that hold down the cover and lift the cover off.
4. The battery will be located beneath the cover.
