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Home/Peugeot/308/Mk3 (P5) 2021-Present/Replace the Key Fob Battery

Replace the Key Fob Battery

These instructions apply to the Peugeot 308 Mk3 (P5) 2021-Present. For other models, please choose your vehicle here.

Last updated: June 6, 2026

Short range or a “key battery low” message on your Peugeot 308 Mk3 (P5, 2021–present) almost always means a tired coin cell. The 308 key uses one CR2032 and you can swap it in a couple of minutes.

What You Need

One CR2032 3 V coin cell — the same on both the plain remote key and the keyless ‘Proximity’ fob.

Swapping the Cell

  1. Press the catch and slide out the emergency blade.
  2. Use a small screwdriver to remove the key cover / split the case.
  3. Lift out the old CR2032 — don’t touch the terminals — noting which way it faces.
  4. Fit the new cell the same way up, observing polarity.
  5. Refit the cover and the blade.

Check the lock and unlock from a few paces.

If It’s Still Dead

  • You can still start it — hold the fob to the start button as you press; the car reads the chip directly.
  • Lock by hand with the blade in the driver’s door.

Frequently Asked Questions

What battery does the Peugeot 308 key take?

A single CR2032 3 V coin cell.

Reprogramming needed after the swap?

No — the fob re-links the moment it has power.

How do I open the 308 key?

Remove the emergency blade, then split the case with a small screwdriver.

Keyless start still failing?

Hold the fob against the start button while pressing it.

No-start with a dash light? Check the code on autodtcs.com. If the car’s flat, see our 308 battery guide.

Disclaimer: The information on this page is provided for general guidance only. Always follow your official service manual and safety precautions when working on your vehicle. We are not responsible for errors, omissions, or any damage resulting from the use of this information.

This website is an independent resource and is not affiliated with, endorsed by, or sponsored by Peugeot. All trademarks and brand names belong to their respective owners.

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Mk3 (P5) 2021-Present
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