Mine lasted about 18 months so, following advice on a previous thread, I replaced the battery with a 2032 (not the 2025 that came out).
It fits ok, being held in place by the key case, and as it's about twice the capacity of the 2025 it should last longer.
I'll let you all know in a few years......
Bye the way - the battery in my keyless Ford Kuga lasted about five years!!