Tesla Key Fob Battery Replacement: Type and Steps by Model
By the EV Fix Guide team · · 7 min read
A Tesla key fob battery replacement takes about five minutes and uses a standard CR2032 coin cell, according to Tesla’s own DIY documentation for the Model 3, Model Y and the 2012–2020 Model S and Model X fobs. You need only the battery and a small plastic pry tool or flat-blade screwdriver.
This guide covers the battery type and replacement steps for each Tesla model, how to fix a key card or phone key that stops working, how to add and remove keys, and what replacement fobs and key cards cost.
In short
- Tesla key fobs for the Model 3, Model Y and 2012–2020 Model S and Model X use a CR2032 coin battery.
- Insert the CR2032 with the positive (+) side facing up, according to Tesla’s Model 3 and Model Y instructions.
- Tesla says the Model 3 and Model Y fob battery lasts up to about a year, and the touchscreen warns you when it is low.
- Key cards have no battery: if one stops working, the car’s reader or the card itself is at fault.
- Adding a new key requires an already-paired key card or authenticated key to confirm it.
- Coin batteries are dangerous if swallowed; keep them away from children.
Which battery does a Tesla key fob use?
Tesla key fobs use a CR2032 3-volt lithium coin cell. Tesla’s DIY service documentation specifies a CR2032 for the Model 3 and Model Y accessory fob and for the 2012–2020 Model S and Model X fobs, and the older Model S/X instructions recommend Panasonic CR2032 batteries. For the redesigned fob that comes with 2021 and newer Model S and Model X, check your Owner’s Manual for the exact battery before buying.
| Model | Default keys | Fob battery |
|---|---|---|
| Model 3 | Key cards and phone key; fob sold as an accessory | CR2032 |
| Model Y | Key cards and phone key; fob sold as an accessory | CR2032 |
| Model S 2012–2020 | Car-shaped key fob | CR2032 (Tesla recommends Panasonic) |
| Model X 2015–2020 | Car-shaped key fob | CR2032 |
| Model S / X 2021+ | Key fob, key card and phone key | Check your Owner’s Manual |
| Cybertruck | Key cards and phone key | No standard fob (key cards have no battery) |
Battery types from Tesla’s DIY documentation. Always confirm against your Owner’s Manual.
How to replace the Model 3 and Model Y key fob battery
These steps follow Tesla’s published DIY procedure for the Model 3 and Model Y accessory key fob.
- 1Place the fob buttons-down on a soft, clean surface.
- 2Release the bottom cover with a small flat tool or plastic pry tool, working gently at the seam.
- 3Lift the old battery off its retaining clips.
- 4Wipe the new CR2032 clean, holding it by its edges. Tesla notes that touching the flat faces can shorten battery life.
- 5Insert the new battery with the positive (+) side facing up.
- 6Line up the cover and press it until it snaps into place, then test lock and unlock.
How to replace the Model S and Model X key fob battery
The car-shaped fob for the 2012–2020 Model S and Model X also takes a CR2032 and the process is similar. Tesla’s instructions for these fobs have you place the fob face-down on a soft surface, release the bottom cover with a small flat tool, swap the battery and refit the cover.
- 1Place the fob face-down on a soft surface.
- 2Use a small flat tool to release the bottom cover.
- 3Remove the old battery, noting which way it faces.
- 4Fit a new CR2032 (Tesla recommends Panasonic) the same way round, avoiding touching its flat faces.
- 5Refit the cover and test the fob next to the car.
Tesla key card not working: what to check
A Tesla key card has no battery; it is an NFC card that the car reads at short range. If it stops working, check where and how you tap it before assuming it is broken.
- Model 3 and Model Y: tap the card on the B-pillar reader just below the camera to unlock, and place it on the center console reader behind the cup holders to drive.
- Remove the card from a metal wallet or phone case with a magnet or other cards stacked on it.
- Try a second key card. If both fail, the car’s reader or the low-voltage system may be at fault.
- If the car is completely unresponsive, the 12V/16V battery may be flat; see frunk won’t open with a dead 12V and the 12V battery guide.
Tesla phone key not working: quick fixes
Most phone key problems come from phone settings rather than the car. The phone key uses Bluetooth and the Tesla app, so the app needs Bluetooth, location access and permission to run in the background.
- 1Check Bluetooth is on and the Tesla app has Bluetooth and location permissions set to always allow.
- 2Turn off battery-saving or low-power modes that stop the app running in the background.
- 3Open the Tesla app once to wake the connection, then try again.
- 4Restart the phone, then do a soft reset of the touchscreen; see our reset guide.
- 5If it still fails, remove the phone key from the car and pair it again.
How to add or remove a Tesla key
Adding or removing a key is done on the touchscreen and always needs an already-paired key card or key to authorize it. Tesla’s Owner’s Manual limits how many keys a car can store, so remove lost or old keys.
- 1Sit in the car with an already-paired key card or key.
- 2Go to Controls → Locks and tap the + to add a key.
- 3Choose key card, key fob or phone key and follow the on-screen prompts, placing the new key on the card reader when asked.
- 4Authenticate by placing an existing paired key card on the reader.
- 5To remove a key, open the key list under Controls → Locks, tap the trash icon next to it and authenticate with a paired key card.
- Remove a lost key card or fob straight away so it can no longer unlock or drive the car.
- When selling a Tesla, remove all your keys and your phone from the car and the Tesla account.
Lost all your Tesla keys? What to do
If you lose every Tesla key card and fob, you can usually still get into and drive the car with your phone key, then use the Tesla app to order new key cards. Pairing a new key always needs an already-paired key card to authenticate, so if your phone key also does not work and no key card is left, you will need Tesla Service to pair new keys after verifying ownership.
Act fast on a lost key. Remove it from Controls → Locks so it can no longer unlock or start the car, and consider turning on PIN to Drive under the car’s Safety settings, which requires a four-digit PIN before the car can be driven, even with a valid key.
Tesla key fob tips: range, battery life and storage
- Replace the fob battery once a year as preventive maintenance; a CR2032 costs only a few dollars.
- If the fob only works up close, try a new battery before assuming the fob is faulty.
- Keep a key card in your wallet as a backup even if you use a phone key or fob every day.
- Do not store fobs next to phones, magnets or other key fobs, which can reduce range.
- Phone key reliability depends heavily on the phone; see our phone key guide for model-specific fixes.
How much does a replacement Tesla key fob or key card cost?
Replacement Tesla keys are sold through the Tesla Shop and service centers. Prices change, so the figures below are hedged typical US prices.
| Item | Typical price | Notes |
|---|---|---|
| CR2032 battery | $2–$8 | Any electronics or grocery store |
| Tesla key card | About $25–$40 | Often sold in packs; pair it yourself on the touchscreen |
| Model 3 / Model Y key fob | About $150–$200 | Accessory fob; pair it yourself |
| Model S / Model X key fob | About $150–$250 | Price depends on generation; may need service to pair |
| Phone key | $0 | Set up in the Tesla app |
Hedged typical 2026 US prices. Check the Tesla Shop for current pricing in your market.
Frequently asked questions
What battery does a Tesla key fob take?
Tesla key fobs for the Model 3, Model Y and the 2012–2020 Model S and Model X take a CR2032 3-volt coin battery, according to Tesla’s DIY documentation. Insert it positive (+) side up in the Model 3 and Model Y fob. For newer 2021+ Model S and Model X fobs, check the Owner’s Manual for the battery type.
How do I know my Tesla key fob battery is low?
The touchscreen shows a message when the key fob battery is low. You may also notice the fob only works close to the car or needs several presses. Tesla says the Model 3 and Model Y fob battery lasts up to about a year in normal use, so replace it yearly or when the warning appears.
Can I drive my Tesla if the key fob battery dies?
Usually yes, as long as you have another key. Model 3, Model Y and Cybertruck owners can use a key card or phone key, and a key card never needs a battery. Model S and Model X owners without a phone key or key card should carry a spare CR2032, because a weak battery makes the fob unreliable and a dead one may stop it working.
How many keys can a Tesla have?
Tesla cars can store a set number of keys, shared between phone keys, key cards and fobs; check your Owner’s Manual for your model’s limit. If you reach the limit, remove old or lost keys under Controls → Locks before adding a new one. Each change needs an already-paired key card to authenticate.
Why does my Tesla keep asking for the key card?
If the car asks for the key card even though your phone is nearby, the phone key connection has dropped. Common causes are Bluetooth turned off, the Tesla app lacking background or location permissions, or a phone battery-saving mode. Re-open the app, check permissions and, if needed, remove and re-pair the phone key.
Full repair guide and cost table
Step-by-step fix, tools and Tesla vs. independent shop vs. DIY prices: Tesla Phone Key or Key Card Not Working: Fix Guide.
Tesla Service $0 - $150 (Free if settings-related; diagnosis if hardware) · independent shop $0 - $60 (Rarely needed) · DIY $0 - $60 (Re-pair free; replacement key cards extra)
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More owner repair stories
- Tesla Service Mode: How to Open It and What to RunThe hidden diagnostics menu every Tesla has, and the four tests worth running.
- How to Reset a Tesla: Soft Reset, Power Off and 12V RebootThree resets, from 15 seconds to 10 minutes. Start with the lightest one.
- Tesla DIY Tool Kit: What You Need (and What Not to Touch)Torx set, jack pads, trim tools. And the jobs you should never do at home.
- Does an Independent Shop Void Your Tesla Warranty?Short answer: no. Here is what the law says and where the limits are.
This guide is for information only. High-voltage components (orange cables) can be lethal — leave them to trained technicians. Not affiliated with Tesla, Inc.