What happens when an electric car runs out of charge?

What’s it actually like to run out of charge in an electric car? Well, apart from the obvious worry and stress before it actually happens, the way they behave in their death throes differs markedly.

Here’s what happened to the 10 cars we've just put through a ‘drive ’em till they die’ range test, along with the number of miles they managed after the indicated remaining range dropped to zero. It should be noted that this ‘emergency buffer’ should be taken as a guide only, because it was influenced by the point on the route that each car began to display zero miles remaining.

BMW i4

Emergency buffer 19 miles

When the i4 started to lose power, it was very gradual, so there was no sense of panic. And when the car finally came to a stop, turning it off and on again restored power to the point where it was able to accelerate back up to 70mph and take us an additional five miles. Having this much emergency power in reserve is fantastic, because it means you can keep up with fast-moving traffic when making your way to a refuge area.

BMW iX3

Emergency buffer 5 miles

With around seven miles of indicated range left, a warning stating ‘drive power reduced’ flashed up on the dashboard, but no loss in power was felt and the car maintained a cruising speed of 70mph for another 15 or so miles. Like the i4, when it finally died, turning the car off and on again restored drive power; this could be the difference between being stuck on the hard shoulder and making it to a refuge area.

Cupra Born

Emergency buffer 10 miles

Despite showing a ‘reduced power’ message and having zero miles on its range readout, the Born was able to keep pace with the other cars as they completed the 50mph section of our test loop and accelerated up to 70mph. It then maintained that speed for a further six miles, before gradually slowing to a crawl. Error messages flashed up on the screen once it was no longer possible to drive at all, but the lights remained on. The power steering also continued to work – helpful when loading the Born onto the recovery truck.

Kia EV6

Emergency buffer 13 miles

The EV6 hit zero miles of range during the stop/start 30mph section, with the electric motor that powers the rear wheels sounding a little groggy when setting off. However, it kept up with the pack throughout the 50mph laps and even got more than halfway through the 70mph stint before power started to ebb away. We managed to coax just over a lap more out of it at 45mph, and then the performance dipped again even with the accelerator flat to the floor. When the EV6 ground to a halt, it was in a controlled manner, and neutral could be engaged in order to facilitate being towed.

Kia Niro EV

Emergency buffer 17 miles

After hitting 0%, the Niro EV happily continued with reduced power until it couldn’t maintain 70mph, from which it began to slowly lose speed. Shortly after, the car automatically put itself in neutral and coasted for just over half a mile. Once the speed reduced to around 3mph, its handbrake was automatically, and suddenly, engaged.

MG ZS EV

Emergency buffer 13 miles

The indicated range dropped to 12 miles before disappearing, but the MG continued to drive. When it could no longer maintain 70mph, it managed to stay at 50mph for a mile or so before its speed gradually but consistently reduced. Curiously, the battery level (a separate readout) remained at 1% even after the car would no longer drive.

Tesla Model 3

Emergency buffer 13 miles

Once the battery percentage reached zero, there was a small warning on the infotainment screen to say that a charge was needed. A few miles later, another warning flashed up to say that the nearest chargers were almost out of range. But after 13 miles from the first warning (with no noticeable loss of power throughout that distance), an audible warning began and, from 70mph, power was reduced until the car came to a complete stop. Once it was stationary, all the interior electronics continued to work as normal – even after recovery.

Tesla Model Y

Emergency buffer 11 miles

Other than the small warning on the infotainment screen, we wouldn’t have known the Model Y was almost out of charge. Until an audible warning began, that was, and then 11 miles later, when a flashing warning was followed very shortly by loss of power. Once the car was stationary, it didn’t take the 12V battery long to lose power, and everything electronic died about 10 minutes later.

Volkswagen ID 5

Emergency buffer 15 miles

Upon reaching 0% indicated range, a message on the instrument panel said the battery was depleted, but the ID 5 continued at 70mph for another 13 miles. At this point, another message came up to say that only manoeuvring was now possible. About half a mile after this message showed, the car began to very slowly lose speed, even with the accelerator pedal floored. The ID 5 completed another two miles before gradually coming to a halt, 15 miles after the range readout had reached 0%. When it stopped, all other functions were available as normal.

Volvo XC40 Pure Electric

Emergency buffer 17 miles

As you would expect from a firm that prides itself on the safety of its cars, the XC40 provided a strong 17 miles of range even after the readout showed 0% and zero miles. After zero, full performance was available for a decent distance, before the maximum speed gradually dropped in 10mph increments – from 70mph to 60mph, 60mph to 50mph and so on. From 10mph, the XC40 gradually slowed to a snail’s pace before stopping.

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