How to Change the Battery in a Mercedes 300E

1. Pop the hood and locate the battery. It's on the passenger side of the engine, toward the firewall of the car, in a sectioned-off area to protect it from heat. Use the open-end wrench to remove the negative then the positive terminal on the battery.
2. Unbolt the battery tie down from the battery using the 3/8-inch ratchet and socket. Lift the tie down off, then lift the battery out of the engine compartment. The battery can now be used as a core exchange at your local auto parts store, or taken for recycling.
3. Place the replacement battery in the battery tray. Bolt in the battery tie down using the ratchet, then connect the positive then the negative battery terminals using an open-end wrench.
4. Start the car and allow it to run for 10 to 15 minutes, then turn it off.