BMW 320i Key Fob Battery Replacement
The F30-style BMW 3 Series key uses one CR2450 3V lithium coin battery, installed positive side up. The Battery Guru CR2450 3V is a two-pack sold for selected BMW 3 Series keys, including the 320i.
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Will This Battery Work in Your BMW 320i Key?
Retailers list this pack for the 320i, and the F30-style BMW key takes a CR2450. BMW says the process differs by model and tells owners to use the same battery type as the one in their key. Run this quick check before you buy.
Not every BMW key uses a CR2450. Some use a CR2032, and some BMW Display Keys have a rechargeable battery. Replacement steps also differ by BMW model. Follow your vehicle-specific owner’s manual.
Battery Guru CR2450 Specifications
| Property | Detail |
|---|---|
| Brand / model | Battery Guru, model BG1-3SeriesCR2450 |
| Battery format | CR2450 coin cell |
| Chemistry | Lithium, single-use (CR2450 cells are lithium / manganese dioxide, non-rechargeable) |
| Nominal voltage | 3 V |
| Dimensions (CR2450 format) | About 24.5 mm diameter × 5.0 mm thick (maximum) |
| Pack size | 2 batteries |
| Marketed for | BMW 3 Series keys, including 320i, 320ix, 328d, 328dx, 328i and 328ix |
| UPC (per listing) | 810162675448 |
| Capacity (reference) | 620 mAh on Panasonic and Energizer CR2450 datasheets. Not verified for this pack. |
| Capacity test (Energizer) | 2.0 V cutoff, 7.5 kΩ load, 21°C |
| Weight (reference) | About 6.2 g (Panasonic) to 6.8 g (Energizer). Not verified for this pack. |
| Operating temperature (reference) | −30°C to +85°C (Panasonic) or −30°C to +60°C (Energizer). Ranges vary by maker. Not verified for this pack. |
| Self-discharge (reference) | About 1% per year (Energizer). Not verified for this pack. |
| Shelf life, origin, cell maker | Not verified |
Rows marked “reference” come from Panasonic and Energizer CR2450 datasheets and describe those makers’ cells, not Battery Guru’s. Battery Guru’s general size guide lists 600 mAh for CR2450, but it does not give test conditions.
BMW 320i Key Battery Replacement Difficulty
For the F30-style key, this is an easy DIY job. The metal key inside the fob opens the cover, and the task needs no soldering or circuit-board removal. The tricky parts are buying the right cell and fitting it the right way up. Tap a slice to highlight it.
- 15% Opening the cover
- 15% Swapping the cell
- 45% Choosing a compatible battery
- 25% Checking polarity & testing
Difficulty score and effort split are an editorial estimate based on the F30 key procedure in BMW’s owner’s manual and FCP Euro’s guide, not an official rating. A worn cover or a different key design can make the job harder.
How to Replace Your BMW 320i Key Battery
These steps apply to the F30-style key with a removable metal key. Tap each step to tick it off as you go.
- 1Remove the metal keyPress the release button on the back of the fob and pull out the integrated metal key.
- 2Release the battery coverPress the metal key into the shallow section opposite the key opening to release the back cover.
- 3Remove the old batteryCheck that the old cell reads CR2450, then lift it out using the small tab on the cover. Keep it away from children and pets.
- 4Insert the new CR2450Place the battery positive (+) side up in the holder.
- 5Close the coverSlide the tab on the bottom of the cover into the fob and press the cover down.
- 6Reinsert the key and testSlide the metal key back in, then test the lock and unlock buttons.
Check that the battery sits positive side up, since a reversed battery is a common cause. If the key still fails, the remote itself may be damaged. Check your vehicle-specific owner’s manual for your key type.
Other Devices That Use a CR2450
CR2450 is a common coin cell format, not a BMW-only battery. Panasonic lists remote keyless entry, card remote controls, memory backup, security price tags and smart transmitter tags as typical uses. Confirm the battery type in your device manual first, and do not swap in a CR2032, which is smaller (20 × 3.2 mm).
- BMW 3 Series keysF30-style, check old cell
- Keyless entry remotesCheck your manual
- Aeotec Multipurpose SensorGP-AEOMPS models
- Older Philips Hue DimmerSeparate on/off buttons
- Card remote controlsSlim remotes
- Memory backupCheck your manual
- Security price tagsRetail tags
- Smart transmitter tagsCheck your manual
The current Philips Hue Dimmer Switch uses a CR2032, so check which version you own.
Safety & Disposal
A swallowed coin battery can burn through a child’s throat or esophagus in as little as two hours. Keep new and used cells out of reach. Get emergency medical help immediately if you suspect ingestion.
- Never try to recharge a CR2450. It is a single-use cell.
- Keep new and used cells away from children and pets.
- Keep used cells out of household trash and recycling bins.
- Tape the terminals or bag each cell, then use a battery collection point or hazardous-waste service.
BMW 320i Key Battery: FAQ
What battery does a BMW 320i key fob use?
The F30-style BMW 3 Series key uses one CR2450 3V lithium coin cell. Key designs differ, so confirm the code on the installed battery or check your vehicle-specific owner’s manual.
How long does a CR2450 last in a BMW key?
No product-specific service life was verified for this Battery Guru pack. Runtime depends on the key, temperature and how often you use it.
Is the CR2450 rechargeable?
No. CR2450 is a single-use primary lithium coin cell format and must not be recharged. Some BMW Display Keys use a different, rechargeable battery.
Do I need to program the key after changing the battery?
The documented battery replacement for the F30-style key has no programming step. Reassemble the key and test the buttons.
Is the Battery Guru CR2450 an original BMW part?
It is a Battery Guru-branded replacement battery sold for selected BMW keys. It has not been verified as a BMW Genuine part.
Can I open the door if the key battery is dead?
On the F30-style key, the integrated metal key can be used to open the door when the remote battery is dead.
How should I dispose of a used CR2450?
Do not put it in household trash or recycling bins. Tape the terminals or bag each cell individually and take it to a battery collection or hazardous-waste service. Keep used cells away from children.
