How long does your key fob last.

I dropped my key fob today when I picked it up I thought I wonder when I'll have to change the battery? My fob has no proximity key and no push to start.

Then I thought how long does a proximity key battery last compared to a regular key fob?

I like the convenience of the proximity key, and push to start. I also find it inconvenient to buy a battery and replace it in the fob. If the batteries have the same life span it's a nonissue.

 

For what it's worth, the proximity key for my Mazda seems to last about 3 years - long enough I'd lost the extra fob battery I'd picked up. I've rarely had a battery not expire from age much longer than that.

 

My mustangs non proximity fob just died for the first time this year. It was 23 years old.... The other key fob still works and is the original battery.