When the battery is removed from the key fob, the fob can lose its ‘memory’ or programming. If the key fob is not working after replacing its battery, a reprogramming procedure may be required.

If you're looking to pick up a new key fob, or repair one, you might wonder how long programming it takes and whether or not you can do it yourself.

If the battery in your car key fob has died, here's how to replace it – including the type of battery you'll need and the cost involved.