These instructions apply to the Tesla Model 3 (2017-2024). For other models, please choose your vehicle here.
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The Tesla Model 3 (2017–2024) normally uses a key card or your phone, but the optional key fob contains a coin cell that can go flat. It’s a quick swap with a CR2032.
Battery First — What You Need
- A CR2032 coin cell.
- A small flat-bladed screwdriver.
Replacing the Cell
- Use a flat-bladed screwdriver to remove the key cover.
- Remove the old cell — don’t touch the terminals.
- Fit a new CR2032 with the positive side facing up.
- Refit the battery cover and the outer cover.
- Test it — use the fob to lock and unlock the car.
Key Card and Phone Key
Even with a dead fob you can still use the key card (tap it on the door pillar, then on the centre console to drive) or your phone key. Replacing the fob cell doesn’t affect pairing.
If a Fresh Cell Doesn’t Help
- Check the orientation — positive side up.
- Use the key card in the meantime.
- Still not working? Re-pair the fob via the touchscreen (Controls > Locks).
Frequently Asked Questions
What battery does the Tesla Model 3 key fob use?
A single CR2032 coin cell, fitted positive-side up.
Do I need to re-pair the fob after the swap?
No — a battery change doesn’t lose the pairing.
Can I still get in with a dead fob?
Yes — use the key card or your phone key.
Does the key card have a battery?
No — the card is passive (RFID) and needs no battery; only the optional fob does.
If the car won’t recognise any key after a 12 V battery issue, see our Model 3 12V 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.
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