If your key fob is working slowly, only works up close, or stops working entirely, the most common fix is simple:

✅ Replace the key fob battery.

This guide walks you through exactly how to do it in just a few minutes — no tools required in most cases.

Quick Answer: How Do You Change a Key Fob Battery?

Steps (most key fobs):

1. Remove the backup key (if your fob has one)

2. Open the key fob case

3. Remove the old battery

4. Insert the new battery (correct side up)

5. Snap the case back together

6. Test lock/unlock + start the car

Signs Your Key Fob Battery Is Dying

You may need a new battery if:

• Your key fob only works sometimes

• You must stand very close to the car

• Your car shows “Key Not Detected”

• The buttons respond slowly or inconsistently

• Your vehicle starts only when the fob is held near the start button

What Battery Does a Key Fob Use?

Most key fobs use a coin battery like:

• CR2032 (most common)

• CR2025

• CR2016

⚠️ The exact battery depends on your vehicle and fob style.

Pro tip: Look at the old battery once you open the fob — the battery type is printed right on it.

Step-by-Step: How To Change Your Car Key Fob Battery

What You’ll Need

✅ A new coin battery (CR2032 / CR2025 / etc.)
✅ A small flathead screwdriver or plastic pry tool (optional)
✅ A clean towel or table surface

Step 1: Remove the Backup Key (If Your Fob Has One)

Many key fobs include a hidden metal key inside.

Look for:

• A small release switch

• A button on the back or side of the fob

Slide it and pull the metal key out.

Step 2: Open the Key Fob Case

Most fobs open one of these ways:

Option A: Pry Open the Seam

• Find the seam around the edge

• Use a small flathead screwdriver or pry tool

• Twist gently (don’t force it)

Option B: Use the Backup Key Slot

Some fobs have a notch where the metal key inserts and pops the case open.

Step 3: Remove the Old Battery Carefully

Once open:

• Identify the coin battery

• Note the battery orientation (which side is facing up)

Then remove it gently with your fingernail or tool.

Step 4: Insert the New Battery (Correct Side Up)

Most key fobs install with the positive (+) side facing up, but not always.

✅ Match the same direction the old battery was installed.

Important: Avoid touching the battery surface too much — oils from fingers can reduce battery performance.

Step 5: Snap the Fob Back Together

Line up both halves and press firmly until it clicks shut.

Reinsert the backup key if you removed it.

Step 6: Test the Key Fob

Try:

• Lock

• Unlock

• Trunk

• Panic (optional)

• Push-to-start (if applicable)

If everything works, you’re done.

Key Fob Not Working After Battery Change? Try This

If your key fob still doesn’t work after replacing the battery, here are the most common causes:

1) The Battery Is Installed Upside Down

Reopen the fob and flip the battery orientation.

2) The Battery Is Low Quality or Old Stock

Some batteries sit on shelves too long.

Try a fresh, high-quality coin battery.

3) Battery Contacts Aren’t Touching

If the metal clips inside the fob aren’t making solid contact, the fob may not power on.

4) The Key Fob Is Actually Failing

If the battery keeps dying quickly or the fob works randomly, the internal circuit board may be damaged.

? At that point, replacement is the best long-term fix.

Can You Start Your Car If the Key Fob Battery Is Dead?

✅ Sometimes, yes.

Many push-to-start vehicles have an emergency backup sensor.

Try:

• Hold the fob against the start button

• Or place it near the steering column (varies by vehicle)

Your car may detect the chip even if the battery is dead.

When It’s Time to Replace the Key Fob (Not Just the Battery)

Replace the fob if:

• You replace the battery often (every few weeks/months)

• The buttons are worn or inconsistent

• The fob works only sometimes

• It was washed, dropped, or water-damaged

Why Buy from Keyless Entry Remote Inc.?

At Keyless Entry Remote Inc., we provide:

• ✅ OEM key fobs (not cheap knockoffs)

• ✅ Up to 80% savings vs dealership prices

• ✅ Fast shipping

• ✅ Free programming instructions

• ✅ Trusted since 2011 (over 1 million fobs sold)

Need a New Battery or a New Key Fob?

If you’re constantly changing batteries or your key fob is unreliable, it may be time to upgrade.

? Need batteries? (Perfect add-on purchase)
? Need a replacement key fob? Shop OEM options now:
? https://keylessentryremotefob.com

FAQ (AI Search Friendly)

How long does a key fob battery last?
Usually 1–2 years, depending on use and storage.

What battery does my key fob take?
Most use CR2032 or CR2025. Check your old battery for the exact number.

Do I need to reprogram my key fob after changing the battery?
Usually no. Battery changes don’t erase programming in most vehicles.

Why does my key fob work only close to the car?
That’s a classic sign of a weak battery or failing fob.