The key fob is your lifeline to your car, letting you unlock the doors and set off the alarm, at a minimum, but how can you tell if it needs a new battery?

Don't panic if your key fob dies and you don't have a replacement battery. These little-known methods will get you back on the road.

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.

There’s usually a mechanical key hiding inside the key fob for cars with push-button start systems, so you can still unlock your door if the car battery or your fob battery runs out of juice.

How much for a car key repair? Car key fob replacement costs have been decried by numerous drivers. Many have accused auto dealerships of exorbitantly pricing the substitution costs of these fobs.