How to Replace a BMW Battery
Operating your BMW's electrical system while the motor is not running is a direct drain on the battery. If your battery is dead, starting the car is impossible without a boost from another vehicle. Here's how to swap the old battery in your BMW for a new one.
Other People Are Reading
Things You'll Need
- Flat-head screwdriver
- 10 mm socket and ratchet or 10 mm wrench
- Phillips-head screwdriver
- New battery
Instructions
-
-
1
Open the trunk. Unlike most American cars, you'll find the battery on a BMW in the trunk, beneath the spare tire covering.
-
2
Remove the two screws securing the battery cover, using a flat-head screwdriver. Lift the battery cover out of the way.
-
-
3
Disconnect the cables from the battery, negative cable first. The negative cable is the black cable connected to the negative lead (marked with a "minus" sign). Use a 10 mm socket and ratchet or a 10 mm wrench to loosen the bolt holding the cable connection around the lead. The positive cable connection will be hidden by a plastic cover that you can remove by hand. Use the 10 mm tool to disconnect the positive cable.
-
4
Using the Phillips screwdriver, unscrew the battery retaining screw that runs the height of the battery. There is a strip of rubber that fits between the screw and the battery; remove it by hand. Keep the strip for reattachment to the new battery (it gives the battery a snug fit when seated).
-
5
Pull the battery up and out from its location.
-
6
Place your new battery into the battery dock. Replace the rubber strip and screw along the side of the battery to hold it into place.
-
7
Attach the positive battery cable to the positive lead. Use a 10 mm socket and ratchet or a 10 mm wrench to tighten the bolt. Tighten the battery cable only enough so that you're unable to move the connection clamp by hand.
-
8
Attach the negative cable. Use a 10 mm tool to tighten the bolt.
-
9
Place the battery cover over the battery, and replace the two screws using the flat-head screwdriver.
-
10
Replace the spare tire lid, and close the trunk.
-
1
Tips & Warnings
Remove the negative battery cable first, then positive. Then replace the positive first, followed by the negative.
