These instructions apply to the BMW X1 Mk2 (F48) 2015-2022.
For other models, please choose your vehicle here.
The remote for a BMW X1 (F48, 2015–2022) that only locks the car from a step away, needs a second or third press, or has stopped responding altogether is almost always suffering from one thing: a flat coin cell. Nearly all F48s left the factory with the familiar slot-in “smart” key — the flat black fob with a metal emergency blade that pulls out of one end — while a few were optioned with the rechargeable BMW Display Key, which is a different animal entirely. Here is how to tell a dying battery from a real fault, the exact cell the standard key needs, and the step-by-step swap you can finish on the driveway in a couple of minutes.
How to Tell the Fob Battery Is Dying
- Shrinking range. You have to be right next to the X1 — or almost touch the fob to the door handle — before it locks or unlocks. This is the first and most reliable sign.
- Comfort Access gets fussy. If your F48 has keyless entry, the door may stop unlocking on a handle touch, or the car may fail to detect the key on the seat when you press Start. A weak cell is the usual cause.
- A dash message. On a keyless X1 the instrument cluster can show a “Remote control battery low” type warning when the fob voltage drops. Treat it as a prompt to change the cell, not an emergency.
- Cold-weather dropouts. A near-flat lithium cell sags further when it is cold, so a key that is fine in summer may misbehave on frosty mornings.
A CR2032 in a BMW fob typically lasts two to four years. If yours is around that age and doing any of the above, fit a fresh cell before you suspect the car’s receiver or the immobiliser.
The Battery You Need
The standard F48 slot-in key takes a single CR2032 3-volt lithium coin cell — the most common fob battery there is, sold in any supermarket, hardware shop or petrol station. Buy a good-quality branded cell; budget batteries can sag under the brief high current the transmitter draws and give short range even when they are “new”. If you pull the old cell and it is marked with a different code, always match what you actually removed rather than assuming.
Method — Standard Slot-In Smart Key
- Release the emergency blade. Press the small button or catch on the side of the fob and slide the metal key blade straight out of its slot. This is the same blade you would use to unlock the driver’s door by hand.
- Open the case. Pulling the blade leaves a small gap at that end of the fob. Insert the emergency blade itself — or a small flat-head screwdriver — into the gap and gently prise the back cover off. It is a snap fit, so it lifts away with light leverage; there is no screw.
- Lift out the old cell. Note which way up it sits before you remove it. On the F48 key the positive (+) side faces up — the face carrying the “CR2032” lettering points towards you, away from the fob body.
- Fit the new cell the same way round, seating it firmly under its retaining clip so it makes clean contact.
- Reassemble. Line up the angled edge of the back cover first, then press it down until it snaps home, and slide the metal blade back into its slot until it latches. Test every button.
⚠️ Get the polarity right. Fitting the cell upside down means the fob simply will not transmit, and a coin cell left in backwards can slowly discharge against the contacts — so copy the orientation of the cell you took out, positive face up.
A Note on the BMW Display Key
If your X1 came with the optional Display Key — the chunkier fob with a small touchscreen that shows fuel range, lock status and climate controls — do not try to open it. It carries a sealed, rechargeable battery rather than a replaceable coin cell, and it tops up wirelessly whenever you set it in the car’s inductive charging tray (or, on some, via a USB cable). If a Display Key stops holding charge, that is a dealer or specialist job, not a DIY cell swap. Everything above applies only to the ordinary slot-in key.
Did It Work?
Stand back a few metres and lock, then unlock, the X1. Full range should return instantly. Any “remote battery low” message clears once the car next reads a healthy fob — sometimes immediately, sometimes after a short drive. If you have Comfort Access, confirm the handle-touch unlock and keyless start are both working again.
If a Fresh Cell Doesn’t Fix It
- Re-check polarity and seating. The commonest mistake is fitting the cell upside down or not pushing it fully under its clip — positive face up, seated firmly.
- Wipe the contacts. A little finger grease or light corrosion on the terminals is enough to cause dropouts; clean them with a dry cloth.
- Try the mechanical blade. If the car still will not respond, use the emergency blade to unlock the driver’s door, then hold the fob against the marked spot on the steering column (or the start button, per your handbook) so the car can read it directly.
- Rule out the car’s 12 V battery. A weak vehicle battery can mimic key faults by leaving the car slow to wake — worth checking separately if the X1 itself feels sluggish to start.
New Key or Spare — Why It’s a Dealer Job
Changing the cell keeps the fob’s existing coding, so nothing needs reprogramming and the key works straight away. Cutting and coding a new key is a different matter: a blank has to be ordered against your X1’s VIN and paired to the car’s immobiliser (the CAS/EWS system) with BMW diagnostic equipment. That makes adding a spare or replacing a lost key a job for a BMW dealer or an auto-locksmith — so keep the battery in your spare key fresh too, and you are never down to a single working fob.
Frequently Asked Questions
What battery does a BMW X1 F48 key take?
The standard slot-in smart key uses a single CR2032 3-volt lithium coin cell. The optional Display Key does not take a replaceable cell — it is rechargeable and sealed.
Which way up does the CR2032 go?
Positive (+) side up — the face with the “CR2032” lettering points towards you, away from the fob body. Always match the orientation of the cell you removed.
Do I need to reprogram the key after changing the battery?
No. A battery swap does not touch the fob’s coding, so it works immediately. Only a brand-new key needs pairing to the car.
How do I open the F48 key without breaking it?
Slide out the metal emergency blade first, then prise the back cover off using that blade or a small flat screwdriver in the gap it leaves. It is a clip fit with no screw, so only light leverage is needed.
How long should the key battery last?
Typically two to four years. Heavy remote use, or leaving a keyless fob sitting close to the car so it wakes constantly, will shorten that.
Can I still drive my X1 if the fob is completely dead?
Yes. Unlock the driver’s door with the emergency blade, then hold the fob against the reader spot noted in your handbook and press Start — the car can read the key directly even with a flat cell, so a dead battery will not strand you.
If the remote died suddenly right after the car’s 12 V battery was disconnected — rather than fading gradually — the cause is more likely the electronics than the coin cell, and the car may have logged a fault in the process. You can look up what a stored code means on autodtcs.com.
Independent guide — not affiliated with BMW. Always follow your official service manual and safety precautions. Read our full disclaimer.