Keyless entry fobs have become standard in many modern vehicles, offering convenience and quick access without turning a key. But as weather in the UK grows more extreme, questions arise about how these smart keys cope with temperature swings. Whether it’s an icy January morning in Yorkshire or a scorcher of a summer’s day in London, climate can impact the way your key fob functions or whether it functions at all.
Let’s take a closer look at how temperature affects your fob, why even a brand-new battery can suddenly fail, and what you can do to prevent unexpected issues.
Across much of the UK, winter temperatures often drop below freezing. While we tend to worry about the car battery in cold weather, key fobs are just as vulnerable.
The biggest issue is the lithium coin battery inside the fob. Cold temperatures significantly reduce battery performance even at just -5°C, the power output can drop noticeably. At -10°C, some fobs may stop responding entirely, even with fresh batteries.
There’s also the issue of condensation. Bringing your key fob from a warm house into a cold car, or vice versa, can cause moisture to build up inside the casing. Over time, this can affect the internal contacts or short the circuit board altogether.
Warning signs to look out for:
The summer of 2022 was a turning point for UK weather. For the first time, temperatures exceeded 40°C in parts of the country a level of heat most vehicles (and drivers) simply aren’t built for.
This kind of heat can cause serious problems for electronic devices, and key fobs are no exception. Left in a vehicle parked in direct sun, the temperature inside can soar past 60°C. At this point, plastic components may start to warp, rubber buttons can soften or crack, and cheap solder joints on the circuit board may weaken.
Batteries, too, suffer in the heat. Prolonged exposure can cause them to swell or leak, even if they’re relatively new. Budget batteries are particularly at risk, as they lack proper thermal protection.
Real-life examples from 2022:
The good news? You don’t need to be at the mercy of the weather. A few simple precautions can go a long way:
If your key fob has suddenly stopped working after a heatwave or frosty night, don’t panic and don’t feel you have to go straight to a dealership. In many cases, the issue can be diagnosed and resolved much faster and more affordably by a qualified specialist.
At Phoenix Car Keys, we offer:
We cover a wide range of vehicle makes and models including Ford, Vauxhall, BMW, Jaguar and more and we offer mobile services if you’re stuck and need help fast.