Fortunately, in this case, things are quite simple. In fact, you can start an EV the same way you can a gas car. The chances of you ever having to do this are slim, though, thanks to the way the power system works in an EV.
Gasoline car batteries are recharged by the car itself, with the alternator (or dynamo, if your car is old enough) generating electricity from the engine's rotations. These batteries are notorious for losing their charge fairly quickly, and if you don't intend to drive your car for a few weeks, it's worth running the engine for around 15 minutes each week to ensure the battery stays charged.
If an EV uses a 12V battery, which most do, the battery will be identical to those found in other cars. However, the smaller battery draws its power from the car's main powertrain battery if its charge level gets too low.
It is important to remember that this loan of charge does not usually occur when the car is plugged in. If you leave an EV on the main battery at zero percent for long enough, the 12V battery will eventually die as well.
Also, in some cases, having a depleted 12V battery can prevent the main battery from recharging. That's not a situation you want to find yourself in.
It's pretty rare for an EV's 12V battery to die completely, but it can happen. In those cases, you can get a jump off of another car, just like you would if your car still used gas. Or you can get a trickle charger to supply power more directly whenever you're not in a hurry.
If you ever need a jump start, the process is exactly the same as if you were driving a gas car. Just be sure to unplug the car from a charger, because otherwise, you risk damaging the car's electrical system.
Can a jump-start give you more range?
No. A jump start only applies to the smaller 12V battery, which cannot transfer power 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 close to what is needed to generate the motors that turn the wheels of an electric car.
Trying to regain lost range from a quick start is completely useless and pretty dumb to try. One of the benefits of driving an electric car is the fact that it does not produce any kind of pollution while driving. Trying to use a gasoline engine to recharge the battery defeats the purpose and means it's like driving a hybrid.
If you need more range, all you have to do is find an EV charging station near you.
Can you use an EV to jump-start another car?
Technically you can, but that doesn't mean you should try to start a gas 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 normal method. This can usually be accomplished by connecting both car batteries 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 frame, not the receiving battery's negative pole.)
But you really shouldn't do this, because you risk causing significant damage to your car.
Why? It seems to be due to how electric vehicles work and what the electric vehicle's 12V battery actually does. In a gasoline-powered car, the battery gives the electric starter the juice it needs to physically move the internal combustion engine fast enough to achieve ignition.
Electric vehicles don't have an ignition circuit, because there's no physical fuel that needs to be ignited, and their 12V batteries lack that same kick. That means they don't have what it takes to start the engine in another car.
Trying to jump out of an EV can put a strain on your 12V battery, which is not good for the battery itself. It can also confuse battery monitoring software, leading to unnecessary headaches in the future and can damage the car's DC-DC converter.
The DC to DC converter is an essential part of an electric car as this is how the 12V battery can draw power from the main battery and it is also how the smaller battery powers low voltage systems such as lights, doors, climate control, and so on. If that converter dies on you, then your electric car is pretty much useless.
That's exactly why many manufacturers specifically advise against using an electric vehicle to start a gasoline vehicle.
The Nissan Leaf owner's manual includes a warning that reads: “The LEAF cannot be used as an auxiliary vehicle because it cannot supply enough power to start a gasoline engine. However, a gasoline-powered vehicle can be used to jump-start the LEAF's 12-volt battery.”
Meanwhile, the manual for the Tesla Model S states that the car cannot be used to start another vehicle and that doing so may damage the Tesla. The manual also notes that using the car as a stationary power source, which qualifies as a jump start, will void the warranty.
You won't be able to do that for much longer anyway. 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 occur on the 2022 Model 3 and Model Y.
Both Nissan and Tesla, and many more, confirm that it's perfectly safe for their electric cars to get a jump start from a gasoline engine as long as the electric vehicles use regular 12V batteries. So don't let the fact that your EV can't be used as a power source put you off.
Bottom Line
As different as electric vehicles are from their gas counterparts, many things remain the same. The 12V battery is probably the best example of that and remains a key component of every car on the road, excluding the few Tesla's that have already switched to lithium-ion batteries entirely.
If you have an electric vehicle, be sure to keep a couple of jumper cables in the trunk, just as you would have done before. Just remember that with electric vehicles, the jump start system is a one-way street: it can receive power, but it can't put it back.
It's unfortunate, but EV owners should be aware that these generous gestures will put their own vehicles at risk. Trying to jump-start someone else's car may be good for your karmic balance, but when the dust clears, your bank balance won't feel the same way.