In the past month or so I've occasionally gotten a key battery low indication when shutting down the car. It doesn't happen every time, perhaps once a week. So I finally decided to change the battery. They cost less that $1.50 each in a 5-pack from Amazon. I keep one battery in the car just in case the battery decides to go bad more quickly some time. The car was about 6 months old when I bought it (176 miles) so the FOB was undoubtedly stored far away from the car for that time. I've had the car for 24 months and the key has been stored in the cup holder 95% of the time in the locked garage. Perhaps the battery life would have been longer if not stored in the car, or maybe not