bmwrepairs: How to replace battery on 2005 BMW 325?

Battery Removal & Installation

When it becomes necessary to replace the battery, select one with sufficient cold cranking amps, with a rating equal to or greater than the battery originally installed. Deterioration and just plain aging of the battery cables, starter motor, and associated wires makes the battery's job more difficult in successive years. As the vehicle ages, the wiring becomes slightly less efficient causing an increase in electrical resistance. Because of this condition, when replacing the battery, it is suggested to choose a battery with a greater capacity.

CAUTION

When replacing a battery, ALWAYS disconnect the negative battery cable first, then disconnect the positive battery cable. When connecting a battery, ALWAYS connect the positive cable first and then the negative battery cable.

WARNING

The E36 models with an electrically operated convertible top require a special battery. This battery is designed to withstand excessive vibration generated by the opening and closing of the top. A battery not designed for this application will be subject to premature failure.

E36 Models

Open the luggage compartment lid and pull back the trunk lining on the right side for the 3 Series models. On Z3 models the battery is centrally located and if installed, the access cover must be removed.

Disconnect the negative battery cable, then disconnect the positive battery cable.

Remove the batter hold down bracket and remove the battery.

The balance of the installation is in reverse order of removal, making sure to connect the positive battery cable first, then the negative battery cable.

Recode the radio.

If equipped with electrically operated windows reinitialize the finger jam protection. To do so:
1. Enter the vehicle and close the doors.
2. Turn the ignition switch to the ON position.
3. Raise the window until fully closed and hold the switch in the closing position for an additional 5 seconds.