Mercedes-Benz S400 Car Battery Replacement at your home or office.

How do mechanics replace the battery?

• A temporary power source might be installed to avoid the possibility of losing radio presets or stored data in the PCM while the battery is out. When the battery is already completely dead, this step is unnecessary.
• The vehicle’s negative cable is removed from the battery, followed by the positive cable. The battery tie down system is loosened and the old battery removed.
• Cable ends and wiring are carefully inspected to ensure cleanliness and no corrosion. In some cases, corrosion can be extreme and the cable may need to be replaced or wiring repaired.
• The new battery is installed and the tie down system is reinstalled. Anti-corrosion compound is applied to the battery terminals. The positive terminal is reconnected followed by the negative terminal.
• Some vehicles, for example some models of BMW, VW, and Audi, may require PCM programming to input battery parameters. This step, performed using a specialized scan tool, is necessary to maximize battery life and prevent electrical system malfunctions.
• The car is started and charging system output is measured and compared against the factory OEM specification to ensure that the new battery will properly recharge. Generally, charging output will be in the range of 13.8 to 14.8 volts but the exact specifications vary by make and model.