Dead Key Fob Battery medium urgency

2024 Honda Accord Dead Key Fob Battery (US): How to Get In, Start, and Replace It

A dead key fob battery on your 2024 Honda Accord can stop remote lock/unlock and may prevent push-button start from recognizing the fob. The good news: you can still get into the car and start it using the built-in emergency key and the backup start method. Then you can replace the coin-cell battery to restore normal operation.

Understanding Your Situation

The coin-cell battery inside the Accord’s smart key fob has dropped below the voltage needed to transmit a strong signal. The car may not detect the fob at normal range, so buttons and passive entry/start features can fail intermittently or completely.

🚀 Immediate Steps to Take

  1. Unlock the door with the hidden mechanical key: slide the release on the fob to remove the emergency key, then insert it into the driver’s door key cylinder (there may be a small cover that pops off) and turn to unlock.
  2. Start the car using the backup method: with the fob inside the vehicle, press/hold the brake and use the fob against/very near the START/STOP button (or the designated detection area) while pressing START/STOP to allow the car to read the fob’s transponder.
  3. Replace the fob battery as soon as practical: open the fob case carefully and install a new coin-cell battery (commonly CR2032 on many Honda smart keys, but confirm by checking the old battery marking or the owner’s manual).

Your Options

DIY key fob battery replacement (coin-cell)

Cost: $3-$12 Time: Same day

Open the smart key fob, remove the old coin-cell battery, and install a new one with correct polarity. Test lock/unlock and starting afterward.

âś“ Pros:
  • Lowest cost and fastest fix
  • No programming required for a simple battery swap
âś— Cons:
  • Risk of cracking the fob shell or losing small parts if pried incorrectly
  • Using the wrong battery type or installing it backwards won’t solve the issue

Battery replacement at a parts store or retailer

Cost: $5-$25 Time: Same day

Buy the correct coin-cell battery and have staff replace it (availability varies by store).

âś“ Pros:
  • Less chance of damaging the fob compared with DIY
  • Convenient if you’re already shopping for the battery
âś— Cons:
  • Service may not be offered for all fob designs
  • Quality varies; incorrect installation can still happen

Dealer service (battery replacement and key check)

Cost: $0-$30 Time: Same day

A Honda dealer replaces the battery and can verify the fob is functioning properly, check for related issues (fob damage, low vehicle battery, interference).

âś“ Pros:
  • Correct battery type and proper handling
  • Helpful if the problem isn’t only the battery
âś— Cons:
  • May require an appointment or travel time
  • Higher cost than DIY in many cases

Replace the key fob (if battery doesn’t fix it)

Cost: $200-$500+ Time: Same day / 1-3 days

If the fob is damaged (water intrusion, broken buttons, cracked circuit board) or still not detected after a new battery, you may need a replacement fob and programming.

âś“ Pros:
  • Resolves failures caused by internal fob damage
  • Restores full smart entry/start functionality
âś— Cons:
  • Most expensive option
  • Programming typically requires a dealer or qualified automotive locksmith

⚠️ What to Avoid

✕ Avoid forcing the fob case open with excessive pressure or metal tools that can crack the shell or damage the circuit board—use gentle, controlled prying at the seam.

âś• Avoid installing the wrong coin-cell size/chemistry or mixing old/new batteries; always match the type printed on the original battery (commonly CR2032, but confirm).

✕ Avoid leaving the fob battery dead for long periods if you rely on passive entry—keep a spare coin-cell in the glovebox or at home to prevent being stranded.

Frequently Asked Questions

Can I start my 2024 Honda Accord if the key fob battery is dead?

Usually, yes. You can unlock the door with the mechanical emergency key, then use the backup start method by holding the fob very close to the START/STOP button (or the designated detection area) while pressing the brake and pressing START/STOP so the car can read the fob’s transponder.

What battery does the 2024 Honda Accord key fob use?

Many Honda smart key fobs commonly use a CR2032 coin-cell, but it can vary by fob version. The most reliable way is to open the fob and read the battery marking, or confirm in your owner’s manual before buying.

Do I need to reprogram the key fob after replacing the battery?

No—replacing the coin-cell battery does not typically require programming. If the fob still doesn’t work after a new battery, the fob may be damaged, the vehicle battery may be low, or there may be interference.

Why does my fob work only when I’m right next to the car?

That’s a classic sign of a weak coin-cell battery. The reduced voltage lowers transmit power, shrinking the effective range before it fails completely.

⏱️ Urgency Note: Moderate urgency: you can often still unlock and start the Accord using the emergency key and backup start method, but replace the battery soon to avoid being locked out or unable to start at an inconvenient time.

Related Information

Need Detailed Information?

Get vehicle-specific key fob compatibility, part numbers, and a complete price comparison for your 2024 Honda Accord.

View Accord Key Fob Guide →

Last updated: 2026-01-04