These instructions apply to the Honda Accord Mk8 (CP/CS) 2008-2012.
For other models, please choose your vehicle here.
When the Accord’s remote only works up close, the fob battery is flat. It takes a single CR1616 coin cell and a couple of minutes, with no reprogramming afterward.
How to replace the key fob battery on a Honda Accord (2008–2012)
- Slide the metal emergency key out of the remote (this usually frees the case).
- Gently split the fob at the seam with a small flat screwdriver or a coin.
- Lift out the old cell and fit a new CR1616, matching the polarity.
- Snap the case shut and reinsert the metal key.
- Press the lock or unlock button five or six times near the car to re-sync, then test it.
A battery change does not erase the remote’s coding, so no dealer or reprogramming is needed — pressing the buttons re-establishes the link with the car.
If it still won’t work with a fresh cell, check the battery is seated the right way round. Adding a brand-new key is different — that needs immobilizer registration with dealer equipment and isn’t a DIY job.
Frequently asked questions
What battery does the fob use?
A single CR1616 3-volt coin cell. Check the marking on the old cell as you remove it and fit the same type.
Do I need to reprogram it?
No. The fob keeps its coding through a battery change; pressing lock/unlock a few times re-syncs it. Reprogramming is only for adding a new key.
Still not working with a new battery?
Check it’s a CR1616 seated with correct polarity. If it still fails, the fob may be water-damaged or the receiver needs checking — a replacement key requires dealer registration.
Independent guide — not affiliated with Honda. Always follow your official service manual and safety precautions. Read our full disclaimer.