Like anything else relying on a battery, you car key fob can die—often at the worst time. Thankfully, these batteries are easy to replace.

How to replace car key battery Most key fobs have a little slot you can use to pop them open with a small flatheaded screwdriver, a butter knife or another key.

New key fobs must be programmed with codes that the vehicle has to read before it unlocks the door or allows starting the engine.

But maybe you’ve experienced the downside: The cost to replace the latest key fobs can be as much as $400 depending on the brand. Then add another $20 to $130 to program it to work with your car.

5 On Your Side Replacing a key fob is expensive. 5 On Your Side shares cheaper options While it's expensive to replace a lost car key fob, there are cheaper options.