Hur byter man det extra batteriet på en Mercedes ML350?

On high-end vehicles, such as the Mercedes ML, an auxiliary battery is installed to ensure that the services are always available even when there is high electrical demand. Let's see how to change it and where it is located.

In our Mercedes ML, the battery is not located in the engine compartment, but under the passenger seat. To access it, we need to push the seat all the way back, remove the floor mat, and lift the plastic covering.

Underneath, we will find a compartment with a vent, which we will remove, and a metal plate that held the vent in place. Underneath these, we will find the starter battery.

Remember that when working on the battery, you should not have the keys inserted in the dashboard and all electrical request buttons should be in the "off" position for safety reasons. Now, let's remove the negative terminal first, then the positive one; remove the battery ventilation.

Now, using a 13 mm wrench, let's remove the bolts that hold the battery in place. This way, we remove the battery clamps and can take it out of its housing.

Now, we access the auxiliary battery, which is positioned on the side. Always remove the negative terminal first, then the positive one. This battery costs around 40 euros when purchased from major e-commerce platforms.

Now, all that's left is to reverse the process to reinstall the auxiliary battery, reposition the starter battery, the plate, the vent, the plastic covering, the floor mat, and put the seat back in place. Job done.