These instructions apply to the Alfa Romeo 147 Mk1 (937) 2000-2011.
For other models, please choose your vehicle here.
When the remote on an Alfa Romeo 147 (2000–2011) starts working only from arm’s length, needs a firm second press, or stops locking the car altogether, the coin cell inside it is almost always the culprit. The 147 used a single style of key throughout its run — the Fiat-group folding “flip” remote shared with the Alfa 156, 166 and GT, with a spring-out metal blade and a three-button head. There is no separate keyless smart fob on this generation, so you only have one procedure to learn. Below is how to tell a flat battery from a real fault, the exact cell it takes, and the manufacturer’s own method for opening the case without cracking it.
How to Tell the Fob Battery Is Dying
- Shrinking range. You have to be right next to the 147 — or almost touching the door with the key — before it responds. This gradual loss of distance is the classic first sign of a tired cell.
- Weak or no LED. The little indicator light in the fob head normally blinks when you press a button; once the battery is low it dims or stops flashing entirely, which is a quick way to confirm the fault is in the key and not the car.
- You need several presses. A cell that has just enough charge to blink the LED but not enough to drive the transmitter will lock or unlock only on the second or third try.
- Cold-morning dropouts. A near-flat lithium cell loses voltage in the cold, so a remote that is fine in the afternoon can go dead first thing on a frosty morning.
A coin cell in a 147 remote typically lasts two to four years. If yours is around that age and doing any of the above, fit a fresh battery before you start suspecting the receiver, the immobiliser or the wiring.
The Battery You Need
The 147 flip remote takes a single CR2032 — a 3-volt lithium coin cell, 20 mm across and 3.2 mm thick. It is the most common fob battery made, sold in any supermarket, hardware shop or petrol station. Buy a good-quality branded cell rather than the cheapest multipack: budget cells sag under the brief current spike the transmitter draws and can give short range even when they read as “new”. Alfa’s own manual simply calls for an equivalent 3-volt cell from a normal retailer, so if in doubt, match the code printed on the battery you remove.
How to Change the Battery — Folding Flip Key
This follows the method in the Alfa Romeo 147 owner’s handbook. Work on a clean surface so the tiny cell and holder cannot roll away.
- Release the blade. Press the button on the fob and let the metal key blade swing out to its open position, then hold it there. Folding the blade out gives you something solid to grip and exposes the opening device.
- Turn the opening device. Using a fine-tipped flat screwdriver, turn the small opening device on the body of the key. This unlocks the internal battery holder rather than forcing the case halves apart.
- Slide out the battery holder. With the device turned, pull the little battery holder straight out of the key. The CR2032 sits inside this carrier — you do not need to split the whole shell open.
- Swap the cell. Note which way up the old CR2032 sits, lift it out, and drop the new one in the same orientation so the polarity (the “bias” the manual refers to) is correct. Handle the new cell by its edge; skin oils on the faces can shorten its life.
- Refit and lock. Slide the holder back into the key and turn the opening device the other way to lock it in place. Fold the blade back in and test every button.
⚠️ Get the orientation right. A coin cell fitted upside down will not power the remote and can slowly discharge against the contacts, so always copy the way the old cell was seated before you close the holder.
Confirm It Worked
Stand a few metres from the car and lock, then unlock, using the remote. Full range should return straight away and the fob’s LED should blink brightly on each press. If the buttons feel notchy or the LED is still faint, open the holder again and check the cell is sitting flat under its clip against clean metal contacts.
If a Fresh Cell Doesn’t Fix It
- Re-check seating and polarity. The single most common mistake is a cell that is upside down or not fully clipped in. It must sit firmly in the holder with clean faces both sides.
- Clean the contacts. A smear of grease or light corrosion on the holder’s spring terminals is enough to cause dropouts — wipe them with a dry cloth or a cotton bud.
- Try the buttons close up. If the remote now works only at very short range with a known-good branded cell, the transmitter or a worn button contact inside the head may be failing — common on high-mileage 147 keys that have been sat on for years.
- Use the blade. Remember the flip blade still locks and unlocks the driver’s door mechanically, so a dead remote never leaves you locked out while you sort the fob.
New Key or Spare — Why It’s a Dealer or Locksmith Job
Changing the battery keeps the fob’s existing coding, so nothing needs reprogramming and the remote works the moment the cell is in. A new or spare key is a different matter: the 147 uses an ID48 transponder paired to the car’s Body Computer and immobiliser, so a blank key has to be cut to the SIP22 blade profile and then coded to the car with diagnostic equipment. On many 147s that also means having the CODE card or the car’s master key to hand. That makes adding a spare a job for an Alfa dealer or an auto-locksmith — so keep the battery in your spare fresh too, and you are never down to one working key.
Frequently Asked Questions
What battery does an Alfa Romeo 147 key fob take?
A single CR2032 3-volt lithium coin cell. The same cell fits the related 156, 166 and GT flip keys, and it is stocked almost everywhere.
Do I have to split the whole key case open?
No. On the 147 you turn a small opening device with a fine screwdriver and slide out an internal battery holder — the coin cell lives in that carrier, so there is no need to prise the two shell halves apart.
Which way up does the battery go?
Fit the new CR2032 the same way round as the one you took out so the polarity is correct. If the old cell has already fallen out, the printed markings normally face outward toward you in the holder — when unsure, compare against a fresh cell’s markings before closing it up.
Do I need to reprogram the key after a battery change?
No. Swapping the cell does not affect the coding, so the remote pairs to the car exactly as before. Only a brand-new key needs coding to the immobiliser.
How long should a 147 key battery last?
Usually two to four years. Frequent locking and unlocking, or a fob that gets knocked and wakes the transmitter, will shorten that.
Can I still drive the 147 if the fob is completely dead?
Yes. Fold out the metal blade to unlock the driver’s door by hand, then use the key in the ignition as normal — the remote only handles central locking, so a flat cell will not stop you starting the car.
If the remote died suddenly rather than fading, or the car throws an immobiliser or central-locking warning after the swap, it is worth reading any stored fault code before spending money on a new key — you can look up what the code means on autodtcs.com.
Independent guide — not affiliated with Alfa Romeo. Always follow your official service manual and safety precautions. Read our full disclaimer.