Key fob battery replacement in Tenerife — usually a €3.11 fix you can do in five minutes.
At Otypro in Tenerife, most “my fob stopped working” calls are just a dead €3.11 coin-cell you swap in five minutes — I tell you when it’s really a programming job instead.
I’m Olexy — I quote and do the work myself. If a fresh coin-cell doesn’t bring your fob back, text me and I’ll tell you straight what it actually needs.
Find the right battery
The number on the battery is its size
Almost every car key fob runs on a flat coin-cell — and the part number tells you exactly what to buy. The digits are the dimensions in millimetres:
| Battery | Size | Notes |
|---|---|---|
| CR2032 | 20 × 3.2 mm | Most common |
| CR2025 | 20 × 2.5 mm | — |
| CR1632 | 16 × 3.2 mm | — |
| CR2450 | 24 × 5.0 mm | — |
That tiny difference is why people grab the wrong one — a 2025 will rattle in a 2032 slot and a 2032 won’t always close in a 2025 holder.
The surest way to know yours: pop the fob open and read the number printed on the old battery. CR2032 and CR2025 cover the big majority; CR1632 and CR2450 show up on some models. Once you know the code, any Ferretería, hardware store, or drugstore has it for about €3.11–6.21. Buy a two-pack and keep the spare in the glovebox.
Good news on programming: you almost never need to re-pair the fob after a battery swap. The battery only powers the little radio inside — your car remembers the fob separately, so it keeps working the moment the fresh cell goes in. (The rare exception: a fob that sat dead for weeks, or a car whose main battery was disconnected, which can need a quick re-pair.)
Do it yourself
Swap the battery in four steps
No tools beyond a coin or a small flat-blade, and about five minutes. If it works after this, you've saved yourself a service call entirely.
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01
Identify the battery
Pick up the exact match for the code you read off the old cell above — or check your owner's manual if the marking's worn off.
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02
Open the case
Most fobs split along a visible seam — slide out the hidden metal key first, then pry gently with a coin or a plastic tool. Some have a small screw under a sticker on the back. Don't force it; the clips snap easily.
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03
Swap it — same way up
Note which way the old battery sat before you lift it out. On most fobs the + (printed) side faces up. Try not to touch the flat faces of the new cell — skin oil dulls the contact over time.
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04
Snap shut, test from a few metres back
Stand away from the car so you know the radio signal is actually reaching it. Touching the car can give a false pass.
Gotcha — upside-down kills it
A coin-cell installed backwards won't power the fob at all. If it's dead right after the swap, pop it open and flip the battery before assuming anything's broken.
Still nothing?
If a known-good fresh battery doesn't bring it back, the battery isn't the problem. Skip to when it isn't the battery below.
The Tenerife part
Why fobs die in the hottest weeks of summer
Coin-cell batteries lose voltage with age and heat. A cell that was already a little weak will read fine one day and then drop below the level the fob needs to transmit after a few hours in a car parked in full sun. That's why so many "it just quit out of nowhere" calls land in the hottest weeks of summer.
If your range has been getting shorter, swap the battery before it quits rather than after you're standing in a car park. Keep the old cell as a backup. More car-key tips on the Otypro blog.
60°C
A marginal coin-cell that works in spring often won't transmit after a day baking in a car parked in full sun.
When a fresh battery doesn’t fix it
You’ve put in a known-good battery and the fob still won’t work. Now it’s worth me coming out. Here’s what it usually turns out to be — and where each one goes.
Most likely
Lost programming
Buttons click cleanly, fob feels normal, but the car ignores it. Common after a fob sat dead for weeks or the car battery was disconnected. I re-pair it at your car.
Sometimes
Damaged fob
Some buttons work and others don’t, or the fob got wet or was dropped and never fully recovered. Sometimes the case is salvageable; often a replacement is the right call. I diagnose at your car.
If you’ve lost it
No fob at all
Lost your only fob? That’s not a battery or a re-pair — it’s a brand-new fob made and programmed from scratch, with ownership verification. Different price, different process.
Brand-specific fob-battery notes on the Mazda, Honda, and Nissan pages. Full pricing across every service on the pricing page.
How much does a key fob battery replacement cost in Tenerife?
I'd rather save you a service call than take one for a battery. Here's the honest math.
Do it yourself
Just the battery
~€3.11–6.21 part
A coin-cell from a ferretería, a supermarket, or any pharmacy. Five-minute swap with the steps above. No service call, no charge from me.
If you'd rather I handle it
On-site visit
from €60 minimum
My minimum visit is from €56, so a battery swap alone is bad math — but the battery is included free if I’m already at your car for programming or another job.
Updated September 2026
Fob battery questions, answered
If yours isn't here, just text me. More on the full FAQ page.
How do I know if it's the battery?
The classic signs: the range drops so you have to be right next to the car, the fob works only sometimes, the buttons feel mushy, or the dashboard shows a "key battery low" message. A fresh coin-cell is a €3.11 fix, so it's always worth ruling out first before paying anyone — including me.
Which battery does my key fob use?
Most are a CR2032 or CR2025 coin-cell. The surest way to know: open the fob and read the number printed on the old battery. The digits are the size — CR2032 means 20 mm wide and 3.2 mm thick; CR2025 is the same width but thinner at 2.5 mm, which is why they're easy to mix up. CR1632 and CR2450 show up on some fobs too.
Do I need to reprogram the fob after changing the battery?
Usually no. Most fobs keep their pairing through a battery swap and work the moment the new battery goes in — the battery only powers the radio, the car remembers the fob separately. Occasionally a fob that sat dead for weeks, or a car whose 12-volt battery was disconnected, needs a re-pair. That's a programming job, not a battery one.
Will you replace the fob battery for me?
I can, but my minimum visit is from €56, and a coin-cell is about €3–6 at any ferretería or supermarket. Paying me to swap a battery alone is bad math — I'd rather you keep the money. It makes sense only if I'm already at your car for programming or another job, where the battery is included if it's needed.
Why does my key fob battery die in the Tenerife summer?
At Otypro in Tenerife I see this every summer: coin-cell batteries lose voltage faster in heat, especially in a car parked in full sun. A battery that was already weak will quit on a hot afternoon, because it drops below the level the fob needs to transmit. If yours is acting up, swap it early and keep the old one as a glovebox backup.
My fob still doesn't work with a new battery — now what?
Then it isn't the battery. The usual culprits are lost programming (buttons click but the car ignores the fob), a damaged fob (got wet or dropped), or a vehicle-side fault. Text me your year/make/model and what's happening — I diagnose at your car and send a written quote first. If it turns out to be the car and not the fob, I tell you that instead of billing for nothing.
I lost my only fob — is that a battery job?
No — that's all-keys-lost, not a battery swap. I generate a brand-new fob from scratch and program it to your car, with ownership verification. The price and process are different. See Lost All Keys for the full breakdown.