How to Replace the Battery in a BMW 735Il

1. Open up the trunk of the BMW 735Il. On the right hand side you will find the luggage compartment under the carpeting. The luggage compartment is where the battery is kept.
2. Use both the open-end wrench and the crescent wrench to detach the positive and negative cables from the top of the old battery. Begin with the negative cable first. Once the cables are disconnected, carefully lift them out of the way.
3. Use the socket wrench to unfasten the bolts that hold the battery in place. Carefully remove the clips on the side of the battery.
4. Use the handle strap provided to carefully lift the battery off the battery terminal. If a handle strap is not present, use a sheet or a towel to lift the battery out to prevent injuring your hand.
5. Place the new battery in exactly the same position as the old battery. Reattach the clips and fix the bolts back in place using the socket wrench.
6. Fix the red wire to the positive connection and the black cable to the negative when reattaching the battery wires. An incorrect connection will stop the battery from working.
7. Put the luggage compartment cover securely back in place and place the carpet over the top. Test your new battery to ensure that it is connected and working correctly.