What Kind of Battery Does My Key Fob Need Guide

Ever had your car refuse to unlock… right when you’re in a hurry?
Chances are, your key fob battery is dying—and you’re wondering, “what kind of battery does my key fob need?”

Here’s the good news: most key fobs use simple 3V lithium coin cells like CR2032 or CR2025, and you can swap them yourself in just a few minutes—no dealer visit, no expensive service.

In this guide, you’ll quickly learn:

How to tell if your key fob battery is low
Exactly how to find the right key fob battery size for your car
The most common types like CR2032 key fob battery and CR2025, and which brands last the longest

If your key fob not working is driving you crazy, keep reading—you’ll know which battery you need and how to replace it like a pro.

Signs Your Key Fob Battery Needs Replacing

If you’re wondering “what kind of battery does my key fob need?” it’s usually because your current one is already fading. Before it dies completely, your car key fob will almost always give you a few clear warning signs.

Low Key Fob Battery Symptoms

Watch for these common signs your key fob battery is going bad:

Reduced range – You have to stand much closer to the car for lock, unlock, or trunk buttons to work. A healthy 3V lithium coin cell (like a CR2032 key fob battery) should work from a reasonable distance.
Inconsistent button response – Sometimes it works, sometimes it doesn’t. You press lock, nothing happens… then it suddenly works a second later. That “on and off” behavior almost always points to a weak keyless entry remote battery.
Dashboard warning – Many newer cars will show a message like “Key fob battery low” or “Replace key battery” on the dash or center screen. If you see that, it’s time to replace the key fob battery ASAP.
Multiple presses needed – You find yourself clicking lock/unlock two or three times before the doors respond. That’s a classic low key fob battery symptom, not just “old buttons.”

How Long Key Fob Batteries Last

Most key fob batteries last about 2–4 years in normal use. The exact key fob battery life depends on:

Cold weather – Freezing temperatures can temporarily weaken a 3V coin cell and shorten overall life.
Frequent use – Constant locking, unlocking, and remote start puts more load on the battery.
Leaving the fob in the car – Many smart keys “talk” to the car nonstop when they’re nearby, which drains the battery faster if you leave the fob inside or very close to the vehicle.

If you’re noticing any of these signs, it’s time to look up your key fob battery size, grab a quality lithium coin cell, and replace it before you end up locked out or unable to start your car.

Most Common Key Fob Battery Types

When people ask “what kind of battery does my key fob need?” they’re almost always talking about a 3V lithium coin cell. These are flat, round batteries that slide into the back of your remote or smart key.

Standard 3V lithium coin cells

Most car key fobs in the U.S. use:

3V lithium coin cells (not alkaline)
Designations that start with “CR” (like CR2032, CR2025, etc.)
One single coin cell per keyless entry remote

Lithium coin cells are used because they:

Last several years
Handle temperature swings better
Provide steady power for wireless signals

CR2032 key fob battery (the most common)

If I had to bet on one size, it’d be the CR2032 key fob battery. It’s the go‑to battery size for a ton of key fobs from brands like Nissan, Hyundai, and many others.

Why CR2032 is so popular:

3V lithium
20mm diameter, 3.2mm thick
Higher capacity than thinner options, so it usually lasts longer
Fits well in most modern smart keys and flip keys

Many replacement remotes, like certain Nissan and Infiniti style keyless entry remotes, are designed around this common CR2032 format, just like the ones we sell for models such as the Nissan Sentra/Versa/Leaf keyless entry remote.

CR2025 vs CR2032: what’s the difference?

Another very common key fob battery is the CR2025. The main differences:

Same diameter: 20mm
Thickness:
- CR2032 = 3.2mm thick
- CR2025 = 2.5mm thick
Capacity: CR2032 usually has more mAh, so it typically lasts longer

Key rules:

Don’t force a CR2032 into a slot made for CR2025 (it can crack the case or stress the board).
Don’t drop a CR2025 into a fob designed for CR2032 if it’s loose; it may make poor contact and cause intermittent keyless entry issues.

Other battery sizes you might see

Some vehicles and slimmer key designs use different sizes like:

CR2016 – thinner, often used in compact remotes
CR2450 – thicker, used in some high‑drain or smart key applications
CR1616 / CR1620 – smaller diameter, common in older or very slim key fobs

All of these are still 3V lithium coin cells, just with different thickness and diameters.

Matching the battery size to your key fob

To match the right key fob battery size:

Check the exact number (CR2032, CR2025, etc.) printed on your old battery
Make sure the new one is the same diameter and thickness
Never “upgrade” size just because it fits tightly; your fob is engineered around a specific battery

If you’re ordering a full replacement remote or shell, product pages (like our BMW keyless entry remote options) will usually list the exact car remote battery type it uses so you can match it perfectly.

How to Tell What Kind of Battery Your Key Fob Needs

When you’re asking “what kind of battery does my key fob need,” there are a few quick ways to get the exact key fob battery size without guessing.

1. Read the Number on Your Old Key Fob Battery

Open the key fob and look directly at the old battery.
You’ll see a code printed on top, like:

CR2032
CR2025
CR2016
CR2450
CR1616 / CR1620

That battery code is your exact replacement. Match it 1:1—same letters and numbers.

2. Check Your Owner’s Manual

Most owner’s manuals list the key fob battery type under sections like:

“Keys and Remote”
“Keyless Entry”
“Smart Key”

You’ll usually see wording like “Replace with a CR2032 3V lithium coin cell.”

3. Use Your Car’s Make, Model, and Year Online

You can also search online using:
“[Year] [Brand] [Model] key fob battery type”

For example:

2018 Honda Civic key fob battery
2019 Ford F-150 key fob battery size

Retailers and key fob sites will list the exact 3V lithium coin cell you need. For specific remotes (like GM/Chevy), product pages such as this 2017–2026 Chevrolet/GMC key fob listing on KeylessBest often show the required battery type right in the description.

4. Typical Battery Types by Brand (General Guide)

This is a quick reference, but always confirm with the old battery or manual:

Honda key fob battery type: CR2032 (most modern models)
Toyota key fob battery: CR2032 / CR2016 depending on the fob style
Ford key fob battery replacement: CR2450, CR2032 (varies by model)
Nissan key fob battery: CR2032
Chevy key fob battery: CR2032 / CR2450 (SUV and truck fobs vary)
Subaru key fob battery: CR2032
VW key fob battery: CR2032 / CR2025

Use this as a starting point, then double-check the actual fob.

5. Why the Exact Battery Size Matters

Using the wrong key fob battery size is a bad idea:

Too thick: You can crack the case or stress the internal board.
Too thin: The battery can move around and lose contact, causing intermittent or dead key fob issues.
Wrong voltage or type: Can damage the circuit or make the keyless entry remote unreliable.

Always match:

Type: CR-series 3V lithium coin cell
Size code: Exact number (2032 vs 2026, etc.)

Do that, and your car key fob battery replacement will be quick, safe, and problem-free.

Step‑by‑Step Key Fob Battery Replacement DIY

If you’re wondering “what kind of battery does my key fob need” and you already have the right 3V lithium coin cell in hand, here’s how to swap it safely at home.

Tools You’ll Need

You don’t need much to do a car key fob battery replacement yourself:

Small flathead screwdriver or precision screwdriver
A coin (nickel or quarter works on many fobs)
Plastic prying tool or guitar pick (helps avoid scratching)
New 3V lithium coin cell (CR2032, CR2025, etc., whatever matches your key fob battery size)

How to Open Your Car Key Fob Safely

Find the seam where the two halves of the keyless entry remote meet.
Look for a small notch or slot on the side or near the key ring hole.
Insert the coin or small flathead into that notch.
Twist gently—don’t force it. Let the clips release one by one to avoid cracking the plastic.
If it’s tight, use a plastic prying tool to work your way around the case.

On some models (like certain Hyundai or Nissan smart keys similar to [these OEM-style remotes](https://keylessbest.com/product/2013-2016-infiniti-nissan-jx35-qx60-altima-maxima-pathfinder-4-buttons-keyless-entry-remote-kr5s180144014-pn-s180144018–

Quick Key Fob Battery Guide by Car Brand

When you’re asking “what kind of battery does my key fob need,” most brands use standard 3V lithium coin cells like CR2032, CR2025, or CR2016. Here’s a quick, U.S.-focused guide so you don’t guess.

Honda key fob battery type

Most modern Honda key fobs use:

CR2032 – Civic, Accord, CR‑V, Pilot (most 2014+ models)
Some older/basic remotes: CR1620 or CR1616

If your Honda has a smart key with push‑button start, odds are it’s a CR2032 3V lithium coin cell.

Toyota key fob battery recommendations

Toyota keeps it simple:

Most smart keys and remotes: CR2032
Some older Corolla/Camry/RAV4 remotes: CR2016

Check the number on your old key fob battery, but for most newer U.S. Toyotas, you’re buying a CR2032 key fob battery.

Ford key fob battery replacement sizes

Ford key fob battery types vary by style:

Flip keys and many standard remotes: CR2032
Some Escape, Fusion, Focus smart keys: CR2450 (thicker, higher capacity)
Older small remotes: CR2016

Always match the key fob battery size printed inside your Ford fob before replacing.

Chevy, Nissan, Subaru, VW common battery types

Most mainstream brands stick to a few common sizes:

Chevy / GMC: Mainly CR2032 for remotes and smart keys
- For example, many newer Chevy remotes like this Chevrolet key fob (PN 13522891) for 2026–2026 models use a CR2032.
Nissan: Mostly CR2032, some older remotes use CR2025
Subaru: Largely CR2032 for keyless entry and push‑start keys
VW: Mix of CR2032 and CR2025, depending on the key design

If you drive a Nissan with a 3‑button keyless entry remote similar to this Nissan Kicks / Rogue Sport fob, you’re almost always looking at a CR2032 3V lithium coin cell.

Luxury brands and special key fob batteries

BMW, Audi, and Mercedes often mix standard and special setups:

BMW:
- Older “diamond” keys: internal rechargeable battery (not user‑replaceable)
- Many newer fobs: CR2450 or CR2032
Audi: Usually CR2032, some use CR2025
Mercedes‑Benz: Most use CR2025 (often two stacked), some use CR2032

On these brands, always open the fob or check the manual before you buy—using the wrong size can cause poor contact or damage.

Smart keys with rechargeable or non‑user‑replaceable batteries

Some newer smart keys don’t use a simple coin cell:

Certain BMW, Tesla, and a few high‑end models use rechargeable or sealed batteries
These often need dealer or specialist service instead of a DIY coin cell swap

If your manual says the key fob battery is “non‑serviceable” or “rechargeable,” don’t force it open. In that case, a car key fob battery replacement usually means visiting the dealer or a trusted key/remote shop.

Best Practices for Key Fob Battery Life

Use Quality Key Fob Batteries

For long‑lasting key fob battery life, don’t cheap out on the brand.

Go-to 3V lithium coin cells:

Brand	Type examples	Why I recommend it
Energizer	CR2032, CR2025, CR2016	Reliable, long shelf life, consistent
Duracell	CR2032, CR2450, CR1616	Strong performance in cold & heat
Panasonic	CR2032, CR1620, CR1616	Great value, stable voltage output

Stick with lithium 3V coin cells (not alkaline) for any car key fob battery replacement.
Avoid no‑name or super cheap coin cells—they can leak, swell, or die early and damage the keyless entry remote.

What to Avoid

No alkaline coin cells in place of lithium
Mixed brands or old loose batteries
Keeping a spare loose in your pocket where it can short out

How to Store Spare Key Fob Batteries

Keep them in the original sealed package until you need them.
Store in a cool, dry place—a glovebox is fine if it doesn’t get extreme heat.
Don’t toss them in a metal tray or cup holder where they can touch coins or keys and discharge.

How Often to Replace a Key Fob Battery

Most key fob batteries last 2–4 years. For preventive maintenance:

Daily driver: replace about every 2–3 years.
Spare key: replace every 3–4 years, or when your main fob needs a new battery.
If you see a “key fob battery low” warning or notice reduced range, replace it ASAP.

When It’s Not Just the Battery

If your key fob not working issues continue even with a fresh CR2032 key fob battery (or the correct size):

Worn buttons – rubber pads cracked or not “clicking.”
Damaged circuit board – from drops, water, or battery leaks.
Programming issues – fob lost sync and needs reprogramming or pairing.

In those cases, you’re usually better off replacing the entire keyless entry remote. For example, if you drive a Honda and your shell or electronics are shot, a complete Honda Fit EX key fob replacement can save you dealer pricing and still work like OEM once programmed.

Where to Buy the Right Key Fob Battery

When you’re asking “what kind of battery does my key fob need,” the next question is usually where to buy it and how to avoid wasting money or getting the wrong one.

Online vs In‑Store

Best places to buy key fob batteries:

Option	Pros	Cons
Auto parts stores	Staff can match your key fob battery size; good brands	Slightly higher price than online
Big box stores	Easy to find CR2032, CR2025, CR2016, etc.	Limited help matching exact models
Pharmacies	Convenient, open late	Smaller selection, higher prices
Online retailers	Huge selection, bulk deals, reviews	Easy to accidentally order wrong size

If you want something already tailored to specific remotes, specialist sites that sell complete key fobs, like those offering a 2010–2014 Subaru Outback keyless entry remote, often clearly list the exact key fob battery type needed, which makes matching and reordering much simpler.

Why Quality Lithium Coin Cells Matter

For car key fob battery replacement, always choose 3V lithium coin cells from solid brands:

Go with Energizer, Duracell, Panasonic.
Skip no‑name or alkaline coin cells – they die faster and can leak.
Quality batteries hold a stable voltage, so your keyless entry remote battery lasts closer to that 2–4 year range.

Spending an extra dollar on a good CR2032 key fob battery is still way cheaper than a trip to the dealer.

How to Make Sure the Battery Matches

Before you buy, double‑check:

Battery code: Match the exact number (CR2032, CR2025, CR2450, etc.) printed on your old battery.
Thickness & size: Don’t swap randomly (for example, CR2025 vs CR2032 are different thicknesses).
Car details: Use your car’s make, model, and year in a “key fob battery number lookup” online.
Product pages: Many fob listings, such as a Jeep key fob replacement for 2026–2026 models, clearly state the correct key fob battery size so you don’t guess.

If the size is wrong, the battery may be loose, make poor contact, or damage the housing.

Why Use a Specialist Retailer

Specialist key fob and remote retailers in the U.S. are a smart middle ground:

They know car remote battery types by vehicle and fob shape.
Listings usually spell out: battery size, voltage, and compatibility.
You avoid dealer markup but still get targeted help.

When I sell or recommend key fobs and batteries, I always include the exact key fob battery number and clear compatibility notes to keep it idiot‑proof for DIY buyers.

Saving Money vs Dealer Prices

Dealers often charge:

$30–$80+ for a simple smart key battery replacement or basic fob battery swap.

Doing a replace key fob battery DIY job with a quality 3V lithium coin cell usually costs:

$3–$8 for a name‑brand coin cell in-store
Even less when buying online multi‑packs

As long as you match the battery code and buy a decent brand, you’ll get the same result the dealer offers at a fraction of the cost.