About Cars

How to Replace a Battery in a BMW 325

1. Locate the battery. On early 325s, the battery will be in the engine compartment under the hood. On later cars, it is in the trunk on the passenger side.
2. Turn the 12-mm nut on the negative (-) battery terminal counterclockwise with the 12-mm wrench five full turns. Twist the terminal left and right to dislodge it from the negative battery post. Pull the negative battery terminal away from the battery.
3. Turn the 12-mm nut on the positive (+) battery terminal counterclockwise with the 12-mm wrench five full turns. Twist the terminal left and right to dislodge it from the positive battery post. Pull the positive battery terminal away from the battery.
4. Loosen the hold-down clamp nut at the base of the battery by turning it counterclockwise with a 10-mm socket on a socket wrench. Remove the hold-down clamp nut and the hold-down clamp. Lift the battery straight up and out of the car.
5. Place the new battery in the battery tray, being careful to orient the positive and negative posts with the positive and negative cables.
6. Install the hold-down clamp and nut and tighten with the 10-mm socket on a socket wrench.
7. Slip the positive battery cable terminal onto the positive post on the battery, and tighten the 12-mm nut by turning it clockwise with a 12-mm wrench.
8. Slip the negative battery cable terminal onto the positive post on the battery and tighten the 12-mm nut by turning it clockwise with a 12-mm wrench.