How Much Range a Handheld Gaming Session Really Costs an EV

At a fast charger outside Duluth last January, the man in the next bay asked whether I was worried about "draining the car" with my Steam Deck plugged into the USB-C port. He was sitting in his own EV with the engine-equivalent off, the cabin slowly cooling, wrapped in a jacket. It was 11 below zero Fahrenheit. I had the heat set to 68 and was playing a roguelike in comfort. We were both trying to save range, and only one of us was doing it in the right place.

I have driven electric since 2016 and I log every charge in a spreadsheet, so I went back through my notes and ran the numbers properly. The short version: the handheld costs you almost nothing. Keeping the car awake costs a little. The climate system is where the real energy goes, and it is also the part people most often get wrong in both directions.

Where the energy actually goes while you wait

When an EV sits parked with the "ignition" on, three separate things draw from the high-voltage battery. The low-voltage system, which runs the computers, screens and USB ports, gets fed through a DC to DC converter. The climate system heats or cools the cabin. And anything plugged into a port pulls a small share through the low-voltage side.

The gaming device is the smallest of the three by a wide margin. A Steam Deck under a demanding game draws somewhere around 15 to 25 watts at the wall, including charging its own battery. A Nintendo Switch in handheld mode is closer to 7 to 10 watts. A phone running a mobile game sits at 3 to 5 watts.

Compare that with the car itself. In my current car, the readout shows roughly 250 to 350 watts just to keep the main computer and screens awake. A heat pump holding the cabin at 68°F in sub-zero weather pulls around 1 to 1.5 kilowatts. Older EVs with resistive heaters can pull 3 kilowatts or more.

A 45 minute stop, measured

Here is what a 45 minute wait costs, using my car's average winter efficiency of 3.4 miles per kWh. The device numbers are my own measurements with a USB-C power meter. The car numbers come from the trip computer and my charging logs, so treat them as one driver's data rather than a lab result.

The Steam Deck session costs about 80 meters of range. The heater costs three and a half miles. The man in the next bay was freezing to protect energy that his phone-sized device was never going to use.

The advice to "turn everything off" is aimed at the wrong thing

Forum threads about waiting in an EV are full of people recommending you switch off the screen, unplug devices and sit in the cold. The device part of that advice saves almost nothing, as the table shows. The cold part saves real energy, but whether it matters depends on where you are.

If you are plugged into a fast charger, the climate load mostly comes from the charger, not from your battery. On a 150 kW session, a 1.4 kW heater shaves under one percent off the charging rate. You will pay for that energy, roughly 50 cents at the $0.48 per kWh my usual network charges, but it will not meaningfully slow the stop. The way public fast chargers price a session matters more here than any setting in the car.

If you are parked without charging, waiting for someone at a ferry or a school pickup, the calculation flips. Every watt comes out of your battery. An hour of resistive heating can cost close to 12 miles. That is when sitting in a jacket starts to make sense, and the handheld on its own internal battery becomes the obvious entertainment choice.

In-car games are a different case

Some cars can run games on the main screen while parked. That changes the numbers, because the game now runs on the car's own computer and requires the whole infotainment system to stay awake, plus the large display at full brightness. In my notes, playing on the car screen added roughly 100 to 150 watts above the idle "awake" figure. Still small next to heating, but ten times what a handheld uses.

We covered which games run on a parked car screen in an earlier piece. If range genuinely matters on a stop, a handheld or a phone is the more efficient option. If the car is charging anyway, play whatever you like.

What I am not sure about

My measurements come from two cars and roughly 40 logged stops with a device running. Other models have different idle draws. Some go into a deeper sleep state faster, some keep cellular modems and sentry-style cameras awake. The car readout itself is not perfectly precise at low loads. I would be surprised if any modern EV used less than 150 watts awake or more than 500, but I have not tested every model, and the range estimate on the dash adds its own noise. If that estimate has ever confused you, here is why it is usually wrong.

Battery age matters slightly too. A degraded pack loses the same kilowatt-hours to heating but has fewer to spare, so the percentage drop looks larger on an older car. It is the same energy, just a bigger slice of a smaller pie.

Something worth trying on your next stop

Next time you wait in the car, note the battery percentage when you park and when you leave, and write down whether the heat or air conditioning was running. Do it once with climate on and once with it off, same device, same length of stop. Two data points from your own car will tell you more than any table, including mine, and you can find more crossovers like this in the games section.