These instructions apply to the Ford EcoSport Mk1 (B515) 2014-2022.
For other models, please choose your vehicle here.
If the remote on your Ford EcoSport (2014–2022) has started working only from arm’s length, ignores you every few presses, or has stopped altogether, the coin cell inside it is almost certainly flat. The EcoSport was sold with two quite different keys over this run: a folding “flip” remote on most trims, and a smart (keyless-entry) proximity fob on push-button-start models such as Titanium. They do not take the same battery — a common and expensive mistake is buying the wrong cell — and they open in different ways. Below is the correct battery for each, how to tell a dying cell from a real fault, and why cutting a brand-new key is the one part of this job you can’t finish at home.
How to Tell the Fob Battery Is Dying
- Shrinking range. You end up standing right next to the car, or pressing the fob against the door handle, before it locks or unlocks. This is the classic first warning.
- The remote’s LED goes dark. On the flip key the little indicator light stops flashing when you press a button once the cell voltage falls too low — a fast way to confirm it’s the fob and not the car.
- A key-battery warning in the cluster. Keyless EcoSport models display a low-key-battery or “key not detected” message when the smart fob is weak, and passive entry (grabbing the handle to unlock) starts to fail before the buttons do.
- Cold-weather dropouts. Intermittent response on frosty mornings is a near-flat cell struggling in the cold; it often recovers a little as the day warms, which is a strong hint the battery is on its way out.
A fob cell in an EcoSport typically lasts two to four years. If yours is older than that and doing any of the above, fit a fresh battery before you start suspecting the receiver or immobiliser.
The Battery You Need
This is the part to get right, because the two keys use different cells:
- Folding flip remote — CR2032. A 3-volt lithium coin cell, the most common fob battery there is, sold in any supermarket or hardware shop.
- Smart keyless (proximity) fob — CR2450. Also 3-volt lithium, but physically larger and thicker than a CR2032. The keyless system listens for the car constantly, so it needs the bigger cell’s extra capacity. A CR2032 is too thin to bridge the contacts in a CR2450 holder, so it simply won’t work — don’t try to substitute one for the other.
If you’re not sure which key you have, look at the shape: the flip key has a blade that folds out of the body at the press of a button, while the smart fob is a fixed rectangular remote with a separate emergency blade that slides out of one end. Whichever you own, buy a good-quality branded cell — cheap coin cells sag under the brief high current the transmitter draws and can give short range even when “new”. When in doubt, read the code printed on the cell you take out and match it exactly.
Method 1 — Folding “Flip” Remote (CR2032)
- Fold the metal blade closed so the fob is a solid block to hold.
- Find the seam that runs around the edge of the case; there is usually a small notch near the blade end. Insert a fine flat-blade screwdriver or a plastic pry tool and gently twist to pop the two halves apart. The flip remote is held by clips, not a screw, so no fastener needs removing.
- Note which way the old cell sits, then lift it out. The new CR2032 goes in positive (+) side up — the printed face showing.
- Press the case back together until the clips click all the way round, then test every button.
Method 2 — Smart (Keyless) Proximity Fob (CR2450)
- Release the emergency blade first: slide the little catch on the fob and pull the mechanical key blade straight out of its slot.
- Use the gap the blade leaves, or a flat plastic tool, to work into the seam and split the case. Twist gently along the join rather than forcing one spot, so you don’t crack the plastic.
- Lift out the old CR2450 and note its orientation. Fit the new cell the same way round — on these fobs the positive (+) face sits upward, but always copy what you removed, as a few Ford proximity keys seat the cell the other way.
- Clip the halves back together, then push the emergency blade home until it latches.
⚠️ Get the polarity right. A coin cell fitted the wrong way round can quietly discharge itself and leave the key dead even though the battery is technically full, so match the orientation of the cell you took out rather than guessing.
Check It Worked
Step back a few metres and lock, then unlock, the car. Full range should return the instant the fresh cell is seated. On a keyless EcoSport the low-key or “key not detected” message clears the next time the car reads a healthy fob — sometimes immediately, sometimes after one short drive. Try the passive functions too: with the smart fob in your pocket, grab the door handle to unlock and press START to make sure the car sees the key without you touching a button.
If a Fresh Cell Doesn’t Fix It
- Re-check polarity and seating. Fitting the cell upside down, or leaving it proud of its clip, is the single most common reason a “new” battery doesn’t help. It must sit flat against clean contacts.
- Confirm the cell size. If you have the smart fob, make sure you fitted a CR2450 and not a thinner CR2032 that can’t reach the terminals.
- Wipe the contacts. A smear of finger grease or a little corrosion on the terminals is enough to cause dropouts — clean them with a dry cloth.
- Warning still showing? The alert can take a couple of key reads to clear. Rarely, a weak car 12-volt battery makes the whole system slow to respond and can mimic a key fault, so if the EcoSport itself is sluggish to wake, look at the vehicle battery before condemning the fob.
New Key or Spare — Why It’s a Dealer Job
Changing the coin cell leaves the fob’s existing coding untouched, so nothing needs reprogramming and the remote works the moment it powers back up. A brand-new key is a different matter. The blade has to be cut to the car, and the transponder inside has to be paired to the EcoSport’s immobiliser with diagnostic equipment; smart fobs also have to be ordered as blanks against the vehicle’s VIN. That puts adding a spare or replacing a lost key firmly in the hands of a Ford dealer or an auto-locksmith — so keep the battery in your spare key fresh too, and you’ll never be left relying on a single working remote.
Frequently Asked Questions
What battery does a Ford EcoSport key fob take?
It depends on the key. The folding flip remote uses a CR2032, while the smart keyless proximity fob uses the larger CR2450. Both are 3-volt lithium coin cells, but they are not interchangeable.
How do I know if I have the flip key or the smart key?
The flip key has a blade that springs out of the body when you press a button. The smart fob is a fixed remote with a separate emergency blade you slide out of the end, and it lets you unlock and start the car without pressing anything — that’s the keyless, push-button-start version.
Which way up does the battery go?
On the flip remote the CR2032 sits positive (+) side up. On the smart fob the CR2450 also normally sits positive side up, but a few proximity keys seat it the other way, so copy the orientation of the cell you removed to be safe.
Do I need to reprogram the fob after changing the battery?
No. A battery swap doesn’t affect the fob’s coding, so it works straight away. Only a completely new key needs programming to the car.
How long should an EcoSport key battery last?
Usually two to four years. Heavy use of the remote, or leaving a keyless fob sitting close to the car so it wakes constantly, shortens that.
Can I still drive the EcoSport if the fob battery is completely dead?
Yes. Use the emergency blade hidden in the fob to unlock the driver’s door by hand. On keyless models the dash will report it can’t detect the key, but you can still start the car — hold the fob against the START/STOP button and press it, and the car reads the fob’s built-in transponder even with a flat cell.
If your remote died the moment the car battery was disconnected — rather than fading over weeks — the fault is more likely the pairing or a stored fault than the coin cell; you can look up what any related code means on autodtcs.com.
Independent guide — not affiliated with Ford. Always follow your official service manual and safety precautions. Read our full disclaimer.