My ‘05 is over 14 years old now and I’m wondering how long the key fob battery will last, assuming a day will come when it’s, well, you know... done.

I’m hoping to avoid having it suddenly die one day, without warning, leaving me stranded, unable to start the car.

The key fob is the stock ‘05 “switchblade” version. Should I get a replacement key fob battery to keep in the glovebox? And can I replace the battery myself, without a special tool or needing to visit the dealer for reprogramming? Or hey... will the key fob work indefinitely, for years to come, with no battery replacement necessary?

 

Pretty sure you can still start the car even with a dead battery. Just unlock the car with the key blade, hop in, and turn the key as usual.

On the later models with the card key, there is a key blade you can pull off. The key blade has no battery in it, and it will still start the car on its own without the card attached.

If you are really curious, then grab a multimeter, pull the battery out, read its voltage, find the technical data sheet for the battery, and there is usually a discharge cycle vs voltage graph to give you an idea how much juice you have left.