Pre-heating your EV battery: keeping your range in winter
Cold temperatures are the ultimate nemesis of any EV battery: as the thermometer drops, so does the battery's performance — and with it its range. The short answer up front: yes, pre-heating your EV is worth it. It protects the battery, gives you more range, and makes your vehicle charge more efficiently. Here's why cold is such a problem for the battery and charging — and how to best pre-heat your EV.
Why pre-heating pays off in winter
An EV battery is usually a lithium-ion battery and, as a result, temperature-sensitive. Its most efficient operating temperature is between 20 and 40 degrees Celsius. At temperatures near the freezing point, the internal resistance of the battery cells rises significantly — with two consequences:
- Higher consumption: on short everyday trips (Green NCAP measured roughly 23 km per half hour), the energy consumption of an EV with an un-preheated battery at sharp sub-zero temperatures rises, depending on the vehicle type, by just under 40 per cent to more than double the standard value.
- Longer charging times: while charging, part of the charging power is first used up as heat just to bring the battery to a temperature where it can work efficiently. In particular with fast charging, a cold battery often cannot reach its maximum charging power at all.
Range feels the effect too: according to research by the Norwegian motoring organisation NAF (Norges Automobil-Forbund), roughly 15 to 30 per cent of range is lost in winter, depending on the vehicle, weather and driving style — and in very deep cold with lots of short trips, even more.
Good to know
If you run the heating while charging, the energy it needs comes directly from the power grid rather than from the battery. So you start off with a full battery and a warm cabin — and battery preconditioning further improves charging performance and efficiency.
How to pre-heat your EV properly
The cold affects not just comfort, but range, charging performance and battery lifespan. Five simple measures get you off warm and energy-efficiently — and are easier on the battery:
Pre-heat while charging
Pre-heat 15 to 30 minutes before departure — ideally while the car is still on the charger or wallbox. The heating energy then comes from the grid instead of the battery, and a pre-heated battery absorbs energy better and delivers noticeably more range.
Pre-condition via the app
Many EVs can be pre-conditioned via the manufacturer's app or the infotainment system. With a fixed departure time — say, morning commutes — simply set it: the vehicle starts off comfortably warm and the battery runs at its optimal state.
Charge indoors, where possible
A garage or carport keeps the cold out and prevents extreme temperature swings. A vehicle parked outdoors cools down much more over night — which slows the charging process and needlessly stresses the battery.
Moderate fast charging in frost
The high energy flow of fast chargers meets a cold battery with high internal resistance at sub-zero temperatures — which shortens the battery's lifespan over time. If your schedule allows, it's better in winter to charge at a slower speed, for example on your home wallbox.
Park in a sheltered spot
Without a garage, parking spots against house walls, under bridges or next to buildings help — there's less wind and frost there. A thermal or protective car cover additionally reduces heat loss over night.
Another dial to turn: the tyres
Often overlooked: tyre pressure and rolling resistance also play a role in winter. Insufficient air in the tyres raises energy consumption further — so a regular pressure check is worth it twice over.
In summary: pre-heating is an everyday convenience, not an extra
Anyone who pre-heats their EV in winter saves range and extends the battery's lifespan. The two most important levers: heating from the grid (pre-heat while charging) and sheltered parking. Combined with a considered charging habit — and a check on tyre pressure — getting through the cold season is far more efficient and less stressful than a cold start.