Charging a smartphone in an electric car: here is the impact on range

The preconceived ideas about electric cars still persist in 2023. We will try to explain why using a smartphone charger or listening to the radio only reduces the range by a tiny amount on an electric vehicle.

Among the preconceived ideas about electric cars, everyone has already heard the famous belief that using the radio, charging a smartphone or even turning on the headlights would drastically reduce the range. Recently, a LinkedIn user recounted an anecdote heard at a car dealership where the salesman claimed that the range would be reduced by 100 kilometers just by charging a smartphone.

We are therefore going to debunk these false truths which are unfortunately always in the minds of certain people, by summarizing the different orders of magnitude involved. In this way, you will have plenty of time to respond factually when you hear nonsense about the loss of autonomy of an electric car.

A question of order of magnitude

The capacity of an electric car’s battery is measured in kilowatt hours (kWh), and depending on the model, the smallest batteries are around 40 kWh, while the largest exceed 120 kWh. In terms of autonomy, they also vary from 300 to more than 700 kilometers in the WLTP cycle.

Reasonably, we can estimate the consumption of high-speed electric vehicles between 15 and 25 kWh per 100 kilometers. Put another way, each kilometer traveled on the highway consumes between 150 and 250 Wh.

On a high-end smartphone, maximum charging powers can reach around 50 Watts, or 50 Wh consumed per hour of charging. It would therefore take 3 to 5 hours of continuous charging of a smartphone at full power to consume the equivalent of a single kilometer of autonomy on the highway..

We are well aware of the absurdity of the initial assertion, since not only plugging in the smartphone does not lose 100 kilometers of autonomy, but even charging it at full power for several hours, the impact will be totally negligible.

Steps to reestablish the truth

Last spring, our colleagues atAutomotive-Clean tackled this problem to set the record straight and effectively measure the energy-consuming equipment of an electric car. The vehicle in question was a Hyundai Ioniq 6, but most of the results apply to all cars.

We learn for example that 10 minutes of defrosting the rear screen consumes 80 Wh, or that the use of two heated seats at full power for one hour consumes 240 Wh. Taking the estimated consumption on the highway of an electric car (between 150 and 250 Wh/km), all this therefore corresponds to an overconsumption of less than two kilometers of autonomy.

Put another way, you will be able to travel only 2 kilometers more if you do without heated seats for an hour of driving. The list of equipment tested includes the headlights, indicators, horn and radio, and the conclusion is always the same: no use of this equipment will significantly affect your range.

The case of heating

As you have seen above, it is not the headlights or the use of the radio that will prevent you from arriving at your destination without a hitch. However, the most energy-intensive item, by far, on an electric car has not been addressed at the moment: it is heating.

You are probably aware that electric cars do not particularly like winter, and the higher consumption is one of the reasons. In practice, consumption linked to heating by ventilation of the passenger compartment can sometimes reach 5 kW for vehicles not equipped with a heat pump.

So, in one hour of operation at full speed — which is a fairly extreme case, but not totally impossible —, a passenger compartment heater can consume around 5 kWh, the equivalent of 20 to 35 kilometers of autonomyor 10% of the battery of a car with a 50 kWh pack.

Another way of looking at things is to consider that at an average speed of 100 km/h without heating, and still with a 50 kWh battery, the range is 250 kilometers while consuming 20 kWh/100 km. Once the heating is running at full speed, consumption increases to 25 kWh/100 km, and the range is then 200 kilometers.

The loss of range linked to the use of full heating is then 50 kilometers, or 20% of the initial range. And if your smartphone was plugged in all that time, you probably wouldn’t have lost even another kilometer.

However, these figures must be qualified: it is extremely rare to activate the heating fully for several tens of minutes. Without a heat pump, the average consumption is around 1 to 2 kW at cruising speed, as our colleagues atClean Automotive on the ID. Buzz from Volkswagen.

The air conditioning

For air conditioning, consumption is much lower, with a maximum of between 1 and 2 kW, and the same applies to the heating of vehicles with a heat pump. The same exercise with an electric car equipped with a heat pump would show losses of autonomy rather located between 10 and 20 kilometers (that is to say between 4 and 8% of battery). This is why it is an option that can be relevant when it is not standard.

In any case, you will have nothing to gain by turning off the radio, unplugging your smartphone or turning off a heated seat: all this causes negligible excess consumption compared to the energy necessary to move the vehicle forward. Only stopping the ventilation system can have a real impact.


To follow us, we invite you to download our Android and iOS application. You can read our articles, files, and watch our latest YouTube videos.

Similar Posts