You can replace an Acura key fob battery yourself in about five minutes

Most Acura key fobs use a coin-cell battery—usually a CR2032 or CR2025—that you can buy at any drugstore or supermarket for a few dollars. The battery sits behind a small door on the fob's flat side. You do not need tools or special knowledge; the whole job is opening the fob, sliding out the old battery, and sliding in the new one. The hardest part is usually finding the seam where the fob opens.

If your fob is cracked, won't hold a battery, or stops working even after you install a fresh one, you will need a replacement fob from an Acura dealer or a locksmith. But if the buttons work and the case is intact, a new battery almost always brings it back to life.

Key Takeaways

  • Acura key fobs typically use a CR2032 or CR2025 coin-cell battery, available at any pharmacy or grocery store for under five dollars.
  • The battery door is usually on the flat side of the fob and opens by sliding or prying gently with a flat tool like a coin or butter knife.
  • Once the door is open, the battery slides out and in—note which side faces up before you remove the old one.
  • If the fob still does not work after you install a fresh battery, the problem is likely the fob itself, not the battery.

Finding the battery door on your Acura fob

Look at the flat side of your key fob. You will see a thin seam running around the edge or across the middle—that is where the battery door slides or hinges. On most Acura fobs, the door is a small rectangular panel on the back or side. Run your fingernail along the seam to feel where it separates from the rest of the fob.

If you cannot see a clear seam, try looking for a small slot or notch. Some fobs have a tiny indentation where you can fit a coin or the edge of a butter knife to pry the door open. Do not force it; if you are pulling too hard, you are probably looking at the wrong spot.

Opening the fob and removing the old battery

Once you locate the seam, use a coin (a dime or penny works well) or a flat butter knife to gently pry the door open. Slide the tool along the seam rather than jabbing at one spot—this spreads the force and keeps you from cracking the plastic. The door should pop off or slide out with light pressure.

Inside, you will see the battery sitting in a small metal holder. Before you remove it, note which side is facing up—the positive side (marked with a +) or the negative side (marked with a −). Take a photo with your phone if you are unsure. Slide the old battery out of the holder, or gently pry it up with your fingernail or the edge of your tool.

Installing the new battery

Buy a replacement battery that matches the number on your old one—CR2032 is the most common for Acura fobs, but check to be sure. Slide the new battery into the holder with the same side facing up as the old one. It should sit flat and click into place without force.

Once the battery is in, close the battery door by sliding it back into the seam or pressing it shut, depending on your fob's design. You should hear or feel a small click. Test the fob by pressing each button—the lights inside should flash, and your car should lock and unlock from a few feet away.

What to do if the fob still does not work

If the buttons light up but your car does not respond, the fob may need to be reprogrammed. Some Acura models reprogram automatically when you insert a new battery; others require you to follow a sequence of button presses or visit a dealer. Check your owner's manual for your model year and trim level—the steps vary.

If the buttons do not light up at all, or if the fob worked before but stops working after you install a new battery, the problem is likely inside the fob itself. A cracked circuit board, corroded contacts, or water damage can prevent the battery from making contact. In that case, you will need a replacement fob from an Acura dealer or a licensed locksmith who can program it to your car.

Where to buy a replacement battery

CR2032 and CR2025 batteries are sold at pharmacies (CVS, Walgreens), grocery stores, hardware stores, and online retailers. A single battery usually costs between one and three dollars. Buy a pack of two or three if you want spares—coin-cell batteries last several years, but having extras on hand means you are never stuck with a dead fob.

Avoid very cheap batteries from unknown sellers online. A name-brand battery from a pharmacy is worth the small difference in price and will last longer and hold its charge more reliably.

Frequently Asked Questions

How do I know which battery my Acura fob uses?

The number is printed on the old battery itself—look for "CR" followed by four digits, usually CR2032 or CR2025. If you cannot read it, check your owner's manual or call your Acura dealer with your vehicle identification number (VIN).

Can I use a different battery if I cannot find the exact one?

CR2032 and CR2025 are similar in size but have different thicknesses. Using the wrong one may prevent the battery door from closing properly or cause poor contact. Stick with the number printed on your old battery.

What if my fob has two batteries?

Some older or larger Acura fobs use two coin-cell batteries. Replace both at the same time, making sure each one sits with the correct side facing up. If only one battery is dead, the fob may still work, but replacing both ensures full power.

Do I need to reprogram my fob after changing the battery?

Most Acura fobs reprogram automatically. If your car does not respond after you install a new battery, check your owner's manual for your model year—some require you to press a button sequence or visit a dealer to sync the fob again.

What should I do with the old battery?

Coin-cell batteries contain small amounts of lithium and should not go in the trash. Most pharmacies and electronics stores have battery recycling bins near the checkout. Drop your old battery there on your next visit.