I changed mine at three years and plan to keep changing them every three years. I have some other things around the house that use the same batteries so I use up the remaining battery life in those devices. If the batteries finally die at home it's no big deal. I keep replacements there. I definitely don't like taking old batteries to the hazmat disposal until they are totally used up.
At least on 3rd gen, there's a warning on the dash that your fob battery is running low. When I see that I replace batteries in both fobs. The car's build date was August 2009, and I believe it's been twice now I've done a change.
I believe you have a gen 2 with SKS? In the Gen 2 owners manual it says the inside warning alarm will beep once when the battery is getting low. I had it happening to me and didn’t know the car was trying to tell me the fob battery was low. Happened when I turned the car off. Just beeped for what I thought was no reason. My spare fob on the other hand. That thing was deader than Disco when I went to use it. At least I know my key opens the door now.
Skibob: You said= Happened when I turned the car off. Just beeped for what I thought was no reason. ***So when you would press the 'power button' off=The car would beep once???
Never and I manually use the lock button to lock doors. I rarely use the key fob and that is why it is still working great and in excellent shape with 1/4 million miles. Door automatically opens as I approach. I've seen countless fobs with busted buttons and must be because they are used so often?
