Key fob batteries typically cost between $3 and $10 per battery, depending on the battery type and where you buy it

The price you pay depends on three things: the battery chemistry (usually CR2032, CR2025, or similar), whether you buy it at a big-box store or a specialty shop, and whether you need one battery or a pack. A single CR2032 costs about $3 to $5 at a drugstore or supermarket, $2 to $4 at a big-box retailer like Walmart or Target, and $1 to $2 if you buy a multi-pack online. Dealership batteries run higher—$8 to $15—because you are paying for the fob to be opened and the battery installed by a technician.

Most car key fobs use a coin-cell battery, which is a flat, round battery about the size of a dime. The model number printed on the battery tells you exactly which one your fob needs. You can find this number by opening your fob at home and looking at the old battery, or by searching your car's year, make, and model online.

Key Takeaways

  • A single key fob battery costs $2 to $5 at most retailers, with dealerships charging $8 to $15 if they install it for you.
  • The most common fob battery is a CR2032, but your specific fob may use CR2025, CR2016, or another model—check the old battery before you buy.
  • Buying a multi-pack of batteries online costs less per battery than buying one at a time, even though you will have extras.
  • Opening and replacing a key fob battery yourself takes two minutes and requires no tools other than a coin or flathead screwdriver.

Where to buy key fob batteries and typical prices

Drugstores and supermarkets stock coin-cell batteries in the watch or electronics aisle. CVS, Walgreens, and Rite Aid typically charge $4 to $6 per battery. Target and Walmart carry them for $2 to $4. These are good options if you need a battery today and do not want to wait for shipping.

Online retailers like Amazon sell multi-packs of 10 or 20 batteries for $8 to $15 total, which works out to less than $1 per battery. The trade-off is shipping time—usually two to five days. If you go through fobs regularly or want to keep spares on hand, a multi-pack saves money over time.

Your car dealership will replace the battery for you while you wait, typically charging $8 to $15 for the service. This is the most expensive option but the fastest if you cannot open the fob yourself or do not want to handle it. Some dealerships will do it free if you are a regular customer or if the fob is still under warranty.

Common key fob battery types and their costs

The CR2032 is the most common fob battery and costs $2 to $5 for a single unit. It is 20 millimeters wide and 3.2 millimeters thick. The CR2025 is slightly thinner and costs about the same. The CR2016 is even thinner and also costs $2 to $5. All three are interchangeable in many fobs, but you should always check your old battery first to be sure.

Less common types like the CR1632 or the older 3V lithium batteries cost $3 to $6 because fewer stores stock them. If your fob uses an unusual battery, ordering online is often faster and cheaper than hunting through local stores. Check the battery model number on your old battery before you search—this takes the guesswork out of ordering.

How long a key fob battery lasts

A typical key fob battery lasts three to four years with normal use. If you use your fob multiple times a day, the battery may last only two to three years. If you use it rarely, it may last five years or longer. The battery will gradually weaken before it dies completely, so you may notice the fob working only at close range before it stops working altogether.

Extreme temperatures can shorten battery life. Leaving your fob in a hot car or exposing it to cold for long periods drains the battery faster than normal storage at room temperature. If you notice your fob is not working as well as it used to, a new battery usually solves the problem within minutes.

How to replace a key fob battery yourself

Most key fobs can be opened with a coin or a flathead screwdriver. Look for a small slot or seam on the edge of the fob. Insert the coin and twist gently until the fob pops open—do not force it, or you may crack the plastic. Some fobs have a small button on the back that releases the battery compartment instead.

Once the fob is open, note which side of the battery is facing up. Remove the old battery and replace it with the new one, making sure the positive side (marked with a + or the shiny side) faces the same direction as the old battery did. Close the fob and test it by pressing a button. If it works, you are done. If it does not, open it again and flip the battery over—you may have installed it backwards.

The entire process takes about two minutes. If your fob does not open easily or if the battery replacement does not fix the problem, take it to a dealership or a locksmith. They can open it without damaging it and can diagnose whether the problem is the battery or something else.

Buying in bulk versus single batteries

A single battery from a drugstore costs $4 to $6, but a pack of 10 from an online retailer costs $8 to $12 total—about $1 per battery. If you have multiple cars, multiple family members with fobs, or if you replace fobs regularly, a multi-pack saves money. The batteries stay good for years if stored in a cool, dry place, so buying extras is not wasteful.

If you only need one battery right now and do not expect to need another for years, buying a single battery locally makes sense. You avoid shipping costs and get the battery when ready. The price difference per battery is small enough that convenience may be worth more to you than the savings.

Frequently Asked Questions

Can I use any CR2032 battery in my key fob?

Most CR2032 batteries are interchangeable, but check your old battery first to be sure. Some fobs use CR2025 or CR2016 instead, which are thinner. The model number is printed on the battery itself. If you buy the wrong size, it may not fit or may not make proper contact inside the fob.

How do I know which battery my fob uses?

Open your fob and look at the old battery. The model number (like CR2032) is printed on it. If you cannot open the fob, search your car's year, make, and model plus "key fob battery" online, and you will find the answer. You can also call your dealership and give them your vehicle information—they will tell you the battery type.

Is it cheaper to replace the battery myself or go to the dealership?

Replacing it yourself costs $2 to $5 for the battery. A dealership charges $8 to $15 for the service. If you are comfortable opening the fob, doing it yourself saves money. If you are worried about damaging the fob or if it will not open, the dealership cost is worth the peace of mind.

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

Make sure the battery is installed with the positive side facing the right direction—flip it over and try again. If it still does not work, the fob may have a broken button or internal damage. Take it to a dealership or a locksmith to diagnose the problem. A new fob costs $200 to $500 depending on your car, so repair is worth trying first.

Can I buy key fob batteries at a gas station?

Some gas stations stock coin-cell batteries, but selection is limited and prices are usually higher than at drugstores or big-box retailers. If you need a battery in an emergency and a gas station is your only option, it is worth checking, but plan ahead and buy from a drugstore or online when you can.