Can you jump start an electric car?

Scared of running out of juice in an electric car or hybrid vehicle? Good news: you can jump start them

You may not have realised it, but electric cars and hybrids come with two batteries. The first of these is the main unit that most will be familiar with – the one that stores the electricity required to power electric motors, often a large lithium-ion unit, charged via a cable.The second, less-thought-about battery is a smaller,12-volt lead-acid battery – the same as can be found in all conventionally powered petrol and diesel cars.

This smaller 12-volt battery not only powers features like the lights and windscreen wipers, but also ensures that the lithium-ion battery can be charged. If you have run out of electricity and need to recharge your car, it's likely that you'll have to jump-start this battery.

Can you jump start an electric car?

You may need to jump start an electric car if its batteries are completely drained. The lithium-ion batteries may not be able to be recharged unless the vehicle is jump started via the 12-volt system, allowing the electronics to operate first.

The process or jump starting an electric or plug-in hybrid vehicle is no different to any other car. What might be harder is locating the 12-volt battery: because there is no engine in the front – as is the case with internal-combustion-engined cars – the location of the 12-volt battery differs between models.

Once you have located the battery, use a battery starter or another vehicle to boost it with appropriate jump leads. In the latter case, you must use a petrol or diesel vehicle as the booster vehicle.

An electric vehicle should not be plugged in to charge when you jump start it. This may fry some of the on-board electronics, causing expensive damage. Instead, leave the vehicle unplugged from its charger, and only plug it in once you’ve completed the jump start.

Can you jump start a hybrid?

Like electric vehicles, plug-in hybrids can also be jump started. The process should, in fact, be easier because the battery will likely be located next to the engine – as it is in a conventional car.

Can you use an electric car as a booster vehicle to jump start other cars?

It's recommended that you don't use an electric or plug-in hybrid car to jump start another vehicle. Doing so can put the electronics at risk and potentially cause serious damage.

Nissan advises owners of the Leaf not to use it as a booster vehicle as its battery can't supply enough power to jumpstart another. Meanwhile, the handbook for each of BMW's PHEVs states that they shouldn't be used for jump starting.