BMW Key Battery Replacement: F-Series, G-Series and Display Key, Step by Step

Your BMW has started showing "Remote control battery discharged" on the screen, or the doors only unlock when the key is practically touching the handle. The battery is a CR2032 on almost every BMW key made since 2012, it costs about two euros, and you can change it in the car park with nothing but the key itself. Here is how, for each key type.

Which battery does a BMW key take?

Key	Cars	Battery	User replaceable?
G-Series key	G20 3 Series, G30 5 Series, G05 X5, G07 X7, G42 2 Series, F40 1 Series, newer 4, 7, 8 Series, iX, i4	CR2032	Yes, two minutes
F-Series key	F30 3 Series, F10 5 Series, F20 1 Series, F15 X5, F25 X3, F32 4 Series and most 2012 to 2019 cars	CR2032	Yes, two minutes
Display Key	Optional on 5, 7 Series, X5, X6, X7 (2015 onwards)	Built-in rechargeable	No battery to change: charge it over USB or on the console tray
E-Series key	E90 3 Series, E60 5 Series, E70 X5 and most 2004 to 2013 cars	Rechargeable VL2020, charges in the ignition slot	Not designed to be opened; a key specialist can replace the cell

A few early F01 7 Series and F10 5 Series keys from around 2009 to 2012 are rechargeable like the E-Series key. If your F-Series key has no visible seam for a battery cover, that is why.

Buy a branded CR2032 (Panasonic, Varta, Energizer, Duracell). The thickness matters: a CR2025 fits the slot but is thinner and may lose contact when the key is bumped.

G-Series key: how to change the battery

1. Release the emergency blade. Push the small catch on the back of the key and pull the metal blade out.
2. Find the slot. At the base of the key, where the blade was, there is a thin slot in the plastic.
3. Push the blade tip into the slot and twist gently. The battery cover lifts off. It is held by clips, not glue, so it should give with light pressure.
4. Note the orientation. The battery sits with the printed positive side facing up, towards the cover.
5. Lift the old cell out with a fingernail or plastic pick and drop the new one in, text side up. Hold it by the edges.
6. Click the cover back on and slide the blade in. Test it at the car.

F-Series key: how to change the battery

The F-Series key opens the same way, with one difference: the cover is a small separate panel on the back, roughly a third of the key's length.

1. Slide the catch and remove the emergency blade.
2. Look at the end of the key where the blade came out. There is a small notch on the edge of the battery panel.
3. Insert the tip of the blade into the notch and lever. The panel pops up.
4. Replace the CR2032 with the positive (text) side facing up.
5. Press the panel back until it clicks, refit the blade.

If your F-Series key has no notch and no panel seam, you have one of the early rechargeable keys. Put it in the key slot in the dashboard and drive for half an hour; it charges while the car is running.

Display Key: there is no battery to change

The Display Key has a built-in rechargeable cell, and BMW does not intend you to open it. When the screen says the battery is low, you have two options:

• USB. Lift the small rubber flap on the bottom edge of the key and plug in the cable that came with it. Any phone charger works.
• Wireless charging tray. If the car has the wireless phone charging pad in the center console, the Display Key charges on it. Put it screen side up.

A full charge takes a couple of hours and lasts a few weeks of normal use. Even with the screen completely dead, the key still unlocks and starts the car, because the transponder does not need the rechargeable cell. More on this key, its case and its quirks in our BMW Display Key guide.

E-Series key: it charges in the car

E-Series keys (roughly 2004 to 2013) use a rechargeable cell soldered to the board. It charges every time the key is in the dashboard slot with the engine running, so for most of the car's life you never think about it. The cell does eventually wear out, usually after ten to fifteen years, and the symptom is a key that only works for a few days after a long drive.

A locksmith or BMW key specialist can open the key and solder in a new VL2020 for a fraction of the price of a new key. Do not try to pry it open yourself; the halves are ultrasonically welded and do not go back together.

Battery completely dead? Start the car anyway

Every BMW with Comfort Access has a fallback, and it works without any battery in the key:

1. Open the door. Pull the emergency blade out of the key. On the driver's door handle, there is a small cap covering the lock; lever it off with the blade (there is a slot underneath the handle for this), unlock, and open the door. The alarm will sound.
2. Start the car. On F and G-Series cars, hold the key against the marked area on the steering column, usually on the right side just below the wheel, or against the start button itself on some models, then press Start while holding it there. The car reads the chip in the key through the plastic. On E-Series cars, put the key in the dashboard slot.

The message "Key not detected" goes away as soon as a new battery is in.

After the battery change

• No reprogramming needed. The pairing is stored in a chip, not in the battery.
• The warning may take one drive cycle to clear. Start the car, drive, switch off, and it is gone.
• Still not working? Open it again and check the battery is text side up. Then try a second battery; cells from bulk packs are occasionally flat out of the packet.

While the key is open on the table

Look at the plastic. BMW keys live in pockets with coins and phones, and the gloss finish on the F and G-Series key scratches and wears shiny within a year or two. A replacement key from BMW is a dealer-only part at several hundred euros, which is the reason most of our customers put a BMW key cover on. The Alcantara version is the same suede as an M steering wheel, every button and the roundel stay visible, and it slides off for the next battery change in two seconds.

Common questions

Other brands: see which battery every car key takes or the Mercedes key battery guide.