Key Batteries & Chips

Typically 2 to 4 years under normal use — battery life shortens if the fob is regularly left within range of the car, as the key continuously exchanges signals with the vehicle and drains faster. Replacing proactively every 1 to 2 years avoids surprise failures.

Both are 3-volt lithium cells with the same 20mm diameter, so a CR2025 physically fits a CR2032 slot — but the CR2025 is thinner with lower capacity, so it lasts less time and may sit loose. Use the exact type your fob was designed for whenever possible.

A key button is the small electrical tactile switch soldered onto the circuit board inside the fob — it registers the press when you push lock, unlock, or boot. It is not the rubber or plastic cap on the outside. You replace it when a button stops responding or only works when pressed hard.