Modern cars have swapped regular keys for key fobs, and most of them use a CR2032 button cell battery. How can you tell if it's weak? How long do they last?

Locked out? Discover how to find your car's physical emergency key, bypass the push-to-start ignition, and get back on the road when your key fob battery dies.

Key fob batteries always seem to die at the worst times. Learn a simple way to test a coin cell, plus which results you'll ...