You can replace a Lexus key fob battery yourself in about five minutes

Most Lexus key fobs use a CR2032 coin-cell battery that you can buy at any drugstore, supermarket, or hardware store for a few dollars. The fob itself is designed to open without tools — you slide or pry the two halves apart, swap the old battery for a new one, and snap it back together. The whole job takes longer to find where you put the fob than to actually do the work.

The exact method depends on which Lexus model and fob generation you have, but the principle is the same across nearly all of them. This guide covers the most common designs. If your fob looks different or won't open the way described here, your owner's manual or a quick search for your specific model year will show you the variation.

Key Takeaways

  • Lexus key fobs almost always use a CR2032 battery, which costs $3 to $8 and is sold everywhere.
  • The fob opens by sliding or prying the two halves apart — no screwdriver needed, though a coin or plastic spoon can help.
  • When you open it, note which side of the battery faces up before you remove it, so you put the new one in the same way.
  • If the fob still does not work after you replace the battery, the problem is likely the fob itself, not the battery.

What battery your Lexus key fob needs

The vast majority of Lexus key fobs use a CR2032 coin-cell battery. This is a flat, round battery about the size of a dime and roughly as thick as two stacked coins. You can find them in the pharmacy section, the electronics aisle, or near the checkout at most drugstores, grocery stores, and big-box retailers. They are also sold online. A single battery costs between $3 and $8 depending on the brand and where you buy it.

Some older Lexus models or specialty fobs may use a CR2025 or CR2016 instead, but CR2032 is by far the most common. If you are not sure which one your fob needs, check your owner's manual, look at the battery compartment inside the fob itself (the size is usually printed there), or search online for your specific model year and fob type. Buying the wrong size is not dangerous — it simply will not fit or work.

How to open your Lexus key fob

Most Lexus fobs split into two halves along a seam that runs around the edge. Look for a small slot or groove on one side of the fob — this is where you apply pressure to separate the halves. You can use your fingernail, a coin, a plastic spoon, or a small flathead screwdriver. Slide or gently pry along the seam until the two halves pop apart. Do not force it; if it does not give after light pressure, you may be pushing in the wrong spot.

Once the fob is open, you will see the battery sitting in a small compartment, usually held in place by a metal clip or just resting in a shaped pocket. The battery is round and flat, and one side will be marked with a + or − symbol. Take a moment to note which side is facing up — this matters when you put the new battery in.

Removing the old battery and installing the new one

Gently lift or slide the old battery out of its compartment. If it is held by a metal clip, you may need to lift the clip slightly first. Once the battery is out, look at the new CR2032 battery and make sure the + side faces the same direction as the old one did. Slide or place the new battery into the compartment with the correct side up, and make sure it sits flat and secure.

If your fob has a metal clip, make sure the clip sits over the battery to hold it in place. The battery should not rattle or move around inside the fob. Close the fob by pressing the two halves together until they snap or click back into place. You may hear a small click or feel resistance as they seat — this is normal.

Testing your fob after battery replacement

Stand a few feet away from your Lexus and press the lock and unlock buttons on the fob. The car should respond — you will usually hear the locks click or see the lights flash. If the fob works, you are done. If it does not, try pressing the buttons a few more times, as the new battery may need a moment to make full contact.

If the fob still does not work after you have replaced the battery and tested it, the problem is likely not the battery. The fob itself may have a damaged circuit board, a broken button, or a worn contact. In that case, you will need to have the fob repaired or replaced by a Lexus dealer or a may have access to locksmith who works on car fobs.

Where to buy a CR2032 battery

CR2032 batteries are sold in most places that carry basic supplies. Drugstores like CVS and Walgreens stock them in the pharmacy or health section. Grocery stores usually have them near the checkout or in the electronics aisle. Hardware stores like Home Depot and Lowe's carry them. Walmart, Target, and other big-box retailers sell them as well. You can also order them online from Amazon, eBay, or the manufacturer's website.

Prices vary slightly by brand and retailer, but a single battery rarely costs more than $8. Some retailers sell multipacks of four or more batteries at a lower per-unit price, which can be worth it if you have multiple fobs or want to keep spares on hand. Name brands like Energizer and Duracell are widely available, but store brands work just as well and often cost less.

Frequently Asked Questions

Can I use a different battery size if I cannot find a CR2032?

No. A CR2025 or CR2016 will not fit properly in a fob designed for a CR2032, and using the wrong size can damage the battery compartment or prevent the fob from closing. CR2032 batteries are inexpensive and widely available — it is worth waiting a day or two to get the right one rather than forcing the wrong size.

What if the fob still does not work after I replace the battery?

The battery itself is probably not the problem. The fob may have a damaged circuit board, a stuck button, or corroded contacts inside. Try cleaning the battery and the metal contacts inside the fob with a dry cloth before you give up, but if that does not help, the fob will need professional repair or replacement.

How often do I need to replace the battery in my key fob?

Most CR2032 batteries last between three and four years with normal use. If you use your fob frequently, the battery may wear out sooner. If you rarely use it, it may last longer. When the fob starts to require multiple button presses or only works from very close range, the battery is running low and should be replaced.

Is it safe to replace the battery myself, or should I go to a dealer?

Replacing the battery yourself is completely safe. There is no risk of electric shock, and you cannot damage the fob by opening it to swap the battery. A Lexus dealer will do the same job for a service fee, but there is no reason to pay for it when you can do it in five minutes at home.

What should I do with the old battery?

CR2032 batteries can be recycled. Many drugstores and retailers that sell batteries also accept used batteries for recycling at no charge. You can also check Earth911.com or call your local waste management office to find a recycling location near you. Do not throw the battery in the trash.