These instructions apply to the Volvo XC40 Mk1 (536) 2017-present.
For other models, please choose your vehicle here.
If the remote for your Volvo XC40 (2017–present) only locks the car from arm’s length, needs a second or third press, or has stopped talking to the car altogether, the coin cell inside it is almost certainly flat. The XC40 — built on Volvo’s Compact Modular Architecture (CMA) — ships with the slim rectangular remote control key that Volvo also uses on the XC60, XC90 and S60/V60 of the same era, and many cars came with a small buttonless Key Tag too. Only the remote control key takes a replaceable battery; the Key Tag’s cell is sealed. Below is the exact cell, the official Volvo way to slide the key apart, and why a brand-new key is a dealer job.
How to Tell the Fob Battery Is Dying
- Shrinking range. You have to stand right next to the XC40 — or hold the key almost against the door handle — before it will lock or unlock. This is the usual first sign.
- Keyless entry drops out. Approaching the car no longer wakes the handles, and the passive lock/unlock and hands-free tailgate become unreliable before the buttons themselves fail.
- A dashboard key message. The XC40 shows a low-key-battery warning in the driver display when it reads a weak fob — treat it as a prompt to change the cell rather than a fault.
- Cold-morning failures. A cell that is nearly flat sags further in cold weather, so the key may work in the afternoon but not first thing.
A CR2032 in an XC40 key typically lasts two to four years. If yours is around that age and doing any of the above, fit a fresh cell before you start suspecting the car’s receiver.
The Battery You Need
The XC40 remote control key uses a single CR2032 3-volt lithium coin cell — the common flat 20 mm cell sold in any supermarket, chemist or hardware shop. It is not the thicker CR2450 that some older Volvo keys used, so don’t let a parts listing for a 2007–2018 S60/XC60 fob mislead you: the modern XC40 key is a CR2032. Buy a good-quality branded cell — cheap ones sag under the brief high current the transmitter draws and can give poor range even when “new”. Handle it by the edges; a thumbprint on the faces can hurt the contact.
Method 1 — XC40 Remote Control Key
- Hold the key with the front face (the one carrying the Volvo logo) upward and the key-ring bracket facing you. You will see a small catch just to the left of the key-ring bracket.
- Slide that catch to the side and slide the front shell off, away from the key-ring bracket.
- Underneath sits a second catch. Slide it across in the same way and slide the rear shell off as well, exposing the battery cover.
- Turn the round battery cover anticlockwise to the OPEN position and lift it away.
- Note how the old cell sits, then ease it out and drop the new CR2032 in the same way up — on this key the positive (+) face sits upward under the cover. Don’t touch the flat faces of the new cell.
- Refit the battery cover and turn it clockwise to lock. Press the rear shell back on until it clicks, then slide it the last few millimetres until a second click confirms it is seated. Refit the front shell the same way and test every button.
⚠️ Get the polarity right. A coin cell fitted upside down makes no reliable contact and can quietly discharge, so always copy the orientation of the cell you removed rather than guessing.
The Key Tag — Why You Can’t Change That One
If your spare is the flat, buttonless Key Tag, don’t try to prise it open: Volvo builds its battery in as a sealed unit, and it isn’t designed to be replaced. When a Key Tag stops being recognised, the fix is a replacement ordered and coded by a Volvo workshop — the same as ordering any new key. The battery-change procedure above applies only to the button remote control key.
Did It Work?
Stand back a few metres and lock, then unlock, the XC40 — full range should return at once. Walk up to the car to confirm keyless entry wakes the handles again, and check the tailgate if you have hands-free opening. Any low-key-battery message in the driver display normally clears the next time the car reads a healthy fob, occasionally after one short drive rather than instantly.
If a Fresh Cell Doesn’t Fix It
- Re-check the cell and its orientation. Make sure it is a genuine CR2032 (not a thinner cell that rattles in the holder), seated firmly under its cover the correct way up.
- Wipe the contacts. A film of finger grease or light corrosion on the terminals is enough to cause dropouts — clean them with a dry cloth before blaming the electronics.
- Confirm the shells clicked home. If the front or rear shell isn’t slid fully back to its second click, the battery cover can lose pressure on the cell.
- Rule out the car. A weak 12 V vehicle battery can occasionally mimic key faults if the car is slow to wake. If the XC40 itself feels sluggish to start, have the main battery checked.
New Key or Spare — Why It’s a Dealer Job
Changing the cell leaves the fob’s coding untouched, so no reprogramming is needed and the key works the moment you reassemble it. Adding a spare or replacing a lost key is different: Volvo keys are matched to the car’s VIN and must be ordered and coded through a Volvo workshop with Volvo’s diagnostic software — there is no owner-side pairing procedure for this generation. So keep the battery in your spare remote fresh too, and never be down to a single working key.
Frequently Asked Questions
What battery does a Volvo XC40 key take?
The button remote control key uses one CR2032 3-volt lithium coin cell. The buttonless Key Tag has a sealed battery that can’t be changed.
Is the XC40 key a CR2032 or a CR2450?
It’s a CR2032. The thicker CR2450 belongs to older Volvo keys (roughly 2007–2018 models); the modern CMA-platform XC40 key takes the thinner 2032.
How do I open the XC40 remote key?
Hold it logo-up with the key-ring bracket toward you, slide the catch beside the bracket and slide off the front shell, then release the second catch and slide off the rear shell to reach the round battery cover, which turns anticlockwise to open.
Do I need to reprogram the key after changing the battery?
No. A battery swap doesn’t affect the coding, so the remote works straight away. Only a brand-new or replacement key needs coding by a Volvo workshop.
How long should an XC40 key battery last?
Usually two to four years. Leaving a keyless fob sitting close to the car, where it wakes repeatedly, tends to shorten that.
Can I still drive the XC40 if the key battery is dead?
Yes. Use the detachable metal emergency blade in the remote to unlock the driver’s door, then hold the key against the start control in the position shown in the owner’s manual and the car will read it and start even with a flat cell.
If your remote died the instant the 12 V battery was disconnected — rather than fading over weeks — the pairing or a stored fault is a more likely culprit than the coin cell; you can look up any logged code on autodtcs.com.
Independent guide — not affiliated with Volvo. Always follow your official service manual and safety precautions. Read our full disclaimer.