The BMW 3 Series has a small engine compartment. Due to the lack of space, the battery mounts in the trunk below the floor. When the battery in your 2001 BMW 325 drains, you need to replace it to get your car back on the road. Buy a replacement battery from a BMW dealer or auto parts retailer and change the battery at home. Most auto retailers will recycle the old battery for you, saving you a disposal fee.
Open the trunk of your BMW 325. Lift the carpet on the passenger side to expose the battery compartment.
Pull the black cover off the top of the battery compartment. Loosen and remove the negative battery cable with a wrench. Repeat the process with the positive cable.
Remove the bolts on the mounting bracket with a wrench. Pull the bracket out of the trunk. Lift the battery out of the trunk. A new or recharged battery should be set in the same position.
