DEAR CAR TALK: I have a 2012 Toyota RAV4 with keyless entry and keyless ignition. If the battery in the key fob dies, and I’m not at home where I can grab the spare key, how do I start the car? – Rich

RAY: Great question, Rich. There’s not just one great answer, but I can give you a bunch of options.

First, look closely at your key fob. Many key fobs hide a temporary, pull-out key inside the key fob case itself. It’s there for just such an emergency. Then you just have to figure out where the hidden keyhole is.

A number of cars hide a keyhole in the driver’s door handle. There’s often a cap that you can pop off with the key, and then use the key to unlock the door.

Inside the car, a few cars have a hidden keyhole to start the car, too. Check your owner’s manual, which often is hidden in the glove compartment.

If you don’t have a hidden key in the key fob, your car may be one of those that now come with “remote services.” In that case, call the manufacturer’s help or roadside assistance line, and if your car is connected, they can unlock the car for you remotely.

No remote services? Try holding the key fob right up against the door near the handle and pulling. Sometimes there’s just enough juice in the battery to allow you to unlock it from a close distance.

Or, if you’re stuck in a parking lot or shopping center, you might be able to swap out the battery. Ask a good Samaritan to loan you the battery from his or her key fob for a minute.

That’ll get you into your car and let you start the engine. Once the engine is running, it won’t shut off when you give back the battery. That’ll get you home, or to a place where you can buy a replacement battery.

If you can get into the car, and you don’t have a backup key, there are ways you can start the car with a dead key fob. Try using the key fob itself to push the start button (touch them together).

A bunch of manufacturers have a backup system built into the start button to allow a car with a dead key fob to start that way. (I believe your Toyota is one of them, Rich).

Other cars have another spot where you can touch the dead key fob that allows the car to recognize it. We saw one that had you put the key fob at the bottom of the cup holder. So check your owner’s manual.

If none of those ideas works, call your favorite roadside assistance company, and see if they’ll bring you a key fob battery. If not, maybe a brick.

You also can consider prevention. A key fob that works only at a closer and closer distance is one that’s got a weakening battery. So is a key fob that requires multiple tries to get the door to open. If you notice these symptoms, change the battery.

You also can make it an annual habit. For less than 10 bucks, you can get a two-pack. Then every year on your wedding anniversary, change your battery and your spouse’s battery. Nothing says “I love you” like chocolates and “I changed your key fob battery, darling.”

Got a question about cars? Email Car Talk’s Ray Magliozzi by visiting the Car Talk website, www.cartalk.com.