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.

And that’s just for the fob. Add another $50 to $100 to get replacement fobs programmed to work with your car and to have a new mechanical backup key made.

Just know that most customer-programmable key fobs will require two current working keys in order to program the new one. RELATED: How to replace your key fob | Your key fob may have hidden features ...

With a key fob programmer, you can program your new key and reprogram faulty key fobs. Our experts have researched Amazon to discover the most popular key fob programmers in the automotive market.

Information about programming many manufacturers' key fobs is available on the Internet, although no one site acts as a central clearinghouse for all car models.

If your key fob is wearing out, find a replacement Ford Escape key fob from these top-rated aftermarket products.

When your Honda key fob runs out of battery, you can take it to a dealership, but it's pricey. It's much cheaper and not too difficult to do it yourself.

“The fob has become a critical part of the security of the car,” he said. The average price for an Audi key fob replacement, including programming, is $500, we were told.