Quick answer: a key fob battery replacement takes about two minutes and costs $3 to $15 for the battery, and most fobs do not need reprogramming after a battery swap. This guide shows which battery your key fob uses, how to change it, and when to call a locksmith. Reputable auto locksmiths register with NASTF, which lets them securely pull the key and immobilizer codes a modern car needs to start.
A dying key fob battery is the most common reason a remote stops working. Before you assume the fob is broken, a fresh battery usually brings it back.
Below we cover the battery size by vehicle, a step-by-step key fob battery replacement, cost, where to buy, and safety.
What Battery Does a Key Fob Use?
Almost every key fob uses a flat coin-cell battery. The most common key fob battery is a CR2032, with the CR2025 and CR1632 also widely used.
The battery size is printed on the battery itself, so open the fob and read the number before you buy. A CR2032 is a 3-volt coin cell about the size of a nickel, and it powers most remotes.
Signs Your Key Fob Battery Is Dying
A weak key fob battery gives clear warnings. Catch them early and you avoid getting stuck at the car.
- You have to stand closer to the car for the remote to work
- The lock or unlock button needs several presses
- The dash shows a low key fob battery warning light
- The fob works sometimes and not others
- The remote range drops from across the lot to a few feet
If you notice any of these, a key fob battery replacement is the first thing to try. It is cheap and quick.
Tools You Need
Key fob battery replacement needs very few tools. Most jobs use only what is in a kitchen drawer.
- A small flat head screwdriver or a coin to pry the fob open
- The correct coin-cell battery, usually a CR2032
- A clean, dry surface so you do not lose the tiny parts
How to Replace a Key Fob Battery
Changing a key fob battery is an easy do-it-yourself job. You need the new battery and a small screwdriver or a coin. Follow the steps below.
Step 1: Open the Fob
Most fobs have a seam or a small slot. Pop out the metal emergency key first, then use a flat head screwdriver or a small screwdriver in the slot to pry the fob open. Twist gently so you do not crack the case.
Step 2: Note the Battery Size
Once the fob is open, look at the old battery. Read the battery size, such as CR2032, before you pull it out, so the new battery matches.
Step 3: Swap the Battery
Slide or lift the old battery out of the holder, taking care near the circuit board. Set the new battery in the same way, with the plus side facing the same direction as the old one.
Step 4: Close the Fob and Test
Snap the two halves of the fob back together until they click, and reinsert the emergency key. Test the lock and unlock buttons on the car to confirm the key fob battery replacement worked.
Do You Need to Reprogram the Fob After a Battery Change?
In almost all cases, no. Changing a key fob battery does not erase the fob's programming, so the remote keeps working with the car.
If the fob still does not work after a fresh battery, the issue is not the battery. A locksmith can test the fob, reprogram it, or replace it if the electronics failed.
Key Fob Battery by Vehicle
Most vehicles use a CR2032, but the exact battery size varies by make and model. Here is a quick guide by brand.
Ford and Lincoln Key Fob Battery
Most Ford and Lincoln key fobs use a CR2032 battery. Push-to-start Ford and Lincoln smart keys also use a single CR2032 coin cell, which is easy to change at home.
Toyota, Honda, and Chevrolet Fob Batteries
Toyota and Honda remotes usually take a CR2032, while some Honda models use a CR2025. Most Chevrolet key fobs use a CR2032 as well, so a CR2032 covers a lot of cars.
Nissan, Kia, and Hyundai Fob Batteries
Nissan, Kia, and Hyundai remotes almost all use a CR2032 battery. A few push-to-start models on these vehicles use a CR2025, so check the old battery on those cars.
Jeep, Dodge, and GMC Fob Batteries
Jeep, Dodge, and GMC key fobs use a CR2032 in most cars. Larger trucks and push-to-start models still use the same coin-cell battery, so one battery type covers most vehicles.
Smart Key and Push-to-Start Fobs
Smart keys and proximity fobs also run on a coin-cell battery, most often a CR2032. Even if your car starts with a button, the fob battery still powers the remote and the proximity sensor for keyless starting.
Where to Buy a Key Fob Battery
Key fob batteries are sold almost everywhere. You can buy them at a pharmacy, a hardware store, a big-box store, or online, and the current price is low.
Walmart sells key fob batteries in 2-packs for about $12.99, and a battery shop like Batteries Plus offers unlimited battery replacement for around $23.99. Read the product package for the battery size before you buy so the new battery is compatible with your fob.
How Much Does Key Fob Battery Replacement Cost?
A single CR2032 battery costs about $3 to $8, and a multi-pack lowers the price per battery. If a shop installs it for you, expect to pay around $10 to $25 including the battery.
Compared to a new key fob, a battery is cheap. A replacement fob with programming can run $60 to $180, so always try a battery first.
Battery Replacement Options and Prices
You have a few options for a key fob battery replacement, at different prices.
- Do it yourself: buy the battery for $3 to $8 and change it in two minutes
- Battery shop: about $10 to $25 including the battery and install
- Auto parts store: sells the battery and may install it while you wait
- Dealer: higher price, and usually not needed just for a battery
- Mobile locksmith: best when the fob needs testing or a new key
For most drivers, the do-it-yourself option is the cheapest and fastest. Compare the current price of a multi-pack, since the price per battery drops when you buy more than one, and a spare battery is handy for the next vehicle in the driveway.
When to Call a Locksmith
Call a locksmith if the fob still fails after a new battery, the buttons are broken, or you need a replacement smart key. A mobile locksmith tests the remote, reprograms it, or cuts and programs a new key fob on site.
A locksmith is also the fast, low-cost choice for a lost fob or a fob that will not start the car. You can confirm your vehicle details with the National Insurance Crime Bureau free VIN check before you order a new fob. Chief of Locks serves Indianapolis 24/7. Call (317) 671-7873.
Key Fob Battery Safety
Coin-cell batteries are small and easy to swallow. Keep coin-cell batteries away from children and pets to prevent internal burns, and recycle the old battery instead of tossing it in the trash. Consumer Reports has a helpful guide on replacing a car key fob for less.