The M35 Infiniti is a full-size luxury car with a six-cylinder engine. To install a new battery, you will need to remove the stock battery first. The battery will be secured to the engine compartment on the passenger side by a mount with two nuts on it. Any standard 12-volt vehicle battery can be the replacement, and you can buy one at an auto parts store for around $50 as of October 2010.
Open the hood and loosen the clamp on the negative battery cable using the 10-mm wrench. Pull the negative battery cable off of the output.
Loosen the securing clamp on the positive battery cable using the 10-mm box wrench. Pull the positive cable off of the output.
Remove the two nuts securing the plastic mount to the battery using the 12-mm box wrench. Pull the plastic mount off of the battery. Pull the stock battery from the engine compartment.
Place the new battery in the place where the stock battery was. Replace the mount to the battery and tighten the nuts to secure the battery in place. Reconnect the battery cables the opposite way that you disconnected them, starting with the negative cable.
