You might not know that electric cars come with two batteries inside. There’s the large battery, which powers the motor and drives the car forward, alongside a second, smaller battery. The second battery powers low-power features such as lights, wipers and locks, and is essential to actually powering the car.
In some high-end cars the second battery is a smaller lithium-ion unit, but in many cases you’ll open the hood to find a regular old 12-volt car battery – the same type you’d find in a car. gasoline, with all the same limitations as to the duration of its charge.
Right now, you might be wondering about the relationship between electric vehicles and jump starting. We’ve all had to start our car at some point, or know someone who has, because those 12-volt car batteries are pretty finicky things.
Do electric vehicles ever need a jump start? Can you start another car with an EV? The answer, unfortunately, is a bit complicated.
Can you start an EV?
Fortunately, in this case, things are quite simple. You can indeed start an electric vehicle in the same way as you can with a gas-powered car. However, the chances of you having to do so are rare, thanks to how an electric vehicle’s power system works.
Gas-powered car batteries are recharged by the car itself, with the alternator (or dynamo, if your car is old enough) generating electricity from engine rotations. These batteries are known to lose their charge quite quickly, and if you don’t intend to drive your car for a few weeks, it pays to run the engine for about 15 minutes every week to ensure the battery stay charged.
If an EV uses a 12V battery, which the majority do, the battery will be the same as those found in other cars. However, the smaller battery draws its energy from the car’s main powertrain battery if its charge level drops too low.
It’s important to remember that this charge borrowing usually doesn’t happen when the car is plugged in. If you leave an EV on the main battery at zero percent long enough, the 12V battery will eventually die too.
Also, in some cases, a discharged 12V battery may prevent the main battery from recharging. This is not a situation you want to find yourself in.
It’s quite rare for an EV’s 12V battery to die completely, but it can happen. In these cases, you can jump out of another car, just like you would if your car was still using gasoline. Or you can get a trickle charger to deliver power more directly provided you’re not in a rush.
If you ever need a boost, the process is exactly the same as if you were driving a gas-powered car. Just be sure to unplug the car from the charger, otherwise you risk damaging the car’s electrical system.
Can a quick start give you more autonomy?
No. A jump start only applies to the smaller 12V battery, which cannot transfer energy to the larger lithium-ion battery that powers the wheels of an electric car. The 12V battery is much less powerful than its big brother and has nothing to do with what it takes to generate the motors that turn the wheels of an electric car.
Trying to recover lost distance from a fast start is totally fruitless and a pretty dumb thing to attempt. One of the advantages of driving an electric car is the fact that it does not produce any pollution while you are driving. Trying to use a gas engine to top up the battery defeats the purpose and means you might as well be driving a hybrid.
If you need more range, just find an EV charging station near you.
Can you use an electric vehicle to start another car?
You can, technically, but that doesn’t mean you should try jump-starting a gas-powered car from an electric or hybrid vehicle.
It is physically possible for an electric or hybrid vehicle to start another car, although the process is a bit different from the usual method. This can usually be accomplished by connecting the two car batteries together with a standard set of jumper cables and waiting for the power to change hands. (In a regular jump-starting procedure between two gasoline engines, you would connect the negative clamp of the cables to a ground point on the receiving car’s chassis, not to the negative pole of the receiving battery.)
But you shouldn’t do this, because it may cause serious damage to your car.
Why? This seems to be due to how EVs work and what the EV’s 12V battery actually does. On a gas-powered car, the battery gives the electric starter the juice it needs to physically move the internal combustion engine fast enough to achieve ignition.
EVs don’t have an ignition circuit, because there’s no physical fuel to ignite, and their 12V batteries don’t have the same kick. That means they don’t have what it takes to start another car’s engine.
Attempting to jump out of an electric vehicle can put a strain on its 12V battery, which is not good for the battery itself. It can also confuse battery monitoring software, causing unnecessary headaches down the road and potentially damaging the car’s DC-DC converter.
The DC-DC converter is an essential part of an electric car, as this is how the 12V battery is able to draw power from the main battery, and this is also how the smaller battery powers the low voltage systems like lights, doors, climate control and so on. If that converter dies on you, then your electric car is pretty much useless.
This is exactly why many manufacturers specifically advise against using an electric vehicle to start a gas-powered vehicle.
The Nissan Leaf owner’s manual has a warning that says “LEAF cannot be used as a booster vehicle because it cannot provide enough power to start a gasoline engine. However, a gasoline engine vehicle can be used to start the battery 12 volts from the LEAF.
Meanwhile, the Tesla Model S manual states that the car cannot be used to start another vehicle, and this may result in damage to the Tesla. The manual also states that using the car as a stationary power source, which a jump start qualifies, will void your warranty.
Either way, you won’t be able to do this much longer. Tesla’s 2021 Model S and Model X cars feature a proprietary 12V lithium-ion battery instead of the more common lead/acid battery. This change is also rumored to come to Model 3 and Model Y 2022.
Nissan and Tesla, and many more, confirm that it is perfectly safe for their electric cars to receive a jump from a gasoline engine as long as the electric vehicles use regular 12V batteries. So don’t be put off by the fact that your electric vehicle cannot be used as a power source.
Conclusion
As different as electric vehicles are from their gas-powered counterparts, a lot of things are still the same. The 12V battery is probably the best example of this and remains a key part of every car on the road, except for the few Teslas that have already switched entirely to lithium-ion batteries.
If you have an electric vehicle, be sure to keep a pair of jumper cables in the trunk, just like you would have before. Remember that with electric vehicles, the jump start system is one-way — you can receive electricity, but you cannot return it.
It’s unfortunate, but EV owners should be aware that these acts of generosity will put their own vehicle at risk. Trying to jumpstart someone else’s car can be good for your karmic balance, but when the dust clears, your bank balance won’t feel the same.
