The Right Way to Jumpstart a Hybrid Electric Vehicle

Can You Jump-start a Hybrid Car?

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Dealing with a dead battery in a hybrid car is somewhat more complicated than a dead battery in a regular gasoline car, but it's probably not quite as bad as you might believe. Why? Well, not all hybrid systems are created equal.

• Since the powertrains are not standardized across the hybrid auto industry, there's a lot of variation across brands and even within the same brand over model year redesigns.
• Many hybrid cars have more than one battery, and they might not be located where you expect them to be.
• Some hybrid cars do need a trip to the dealership if the battery dies.
• Some new hybrid models can jump-start themselves.

Jump-starting any car is dangerous if you don't know what you're doing. Hybrids add extra anxiety to the procedure. In general, hybrid vehicles can be jump-started just like a regular car with a conventional gas engine. Not all traditional gasoline cars are the same, of course, but all gas powertrains work pretty much the same, which makes it easy to learn how to jump-start a gas car. However, the unusual layout of many hybrids' powertrains can cause some confusion at first.

Most hybrid models have two distinct batteries: the main high-voltage battery in the powertrain, which takes over when the car isn't using its gasoline engine or runs in tandem with the gas engine for better efficiency, and a smaller 12-volt battery tasked primarily with starting the vehicle, which can be located under the hood but is often located in the trunk. The presence of a hybrid's high-voltage battery pack is most likely why some people believe it's unsafe or impossible to jump-start a hybrid, but those batteries should be easy to tell apart from the smaller, more conventional 12-volt battery used for starting the car (and thus, jump-starting). A hybrid battery pack should be sealed, to prevent electric shocks caused by accidental contact, and should be marked with warning labels. Be extra careful to ensure you're working with the correct battery, and you should be fine.

Both of those batteries can run out of juice, and if you're having battery trouble, you'll have to determine which battery is the source of your problems. If your car won't start, and jump-starting doesn't work, you'll need a mechanic to look at the main hybrid battery.

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A lot of Toyota hybrid models, like the Prius, feature a jump-start terminal under the hood, which you should use instead of the 12-volt battery. Once you have located this terminal, the steps to jump-start the hybrid are pretty much the same as jumping any other car. (If you're stranded on the side of the road right now with a Toyota hybrid, this video about jumping a Toyota hybrid may be exceedingly helpful.)

Before assuming that you need a jump-start, make sure that you aren't actually out of gas. Some hybrid vehicles, like the discontinued Chevrolet Silverado and Nissan Altima hybrids, shut down when the gas tank runs empty, even if the battery is fully charged, notes Popular Mechanics. Others, like those from Toyota and Lexus, can run a short distance (like a couple miles, at most) as long as the main battery had a good charge.

By the way, if you need to use a hybrid car to jump-start another car, the smaller 12-volt battery is what you'll need to use. In a lot of hybrids, like the Toyota Prius, it is located in the trunk instead of under the hood, and the terminals should be marked with plus (+) and minus (-) posts like the battery of a regular car. If you don't find the battery in the trunk, or you don't see marked terminals for jump-starting, check your owner's manual.

So far, we've been careful to say that "most" regular cars have a 12-volt battery responsible for starting duty. That is because until 2017, every modern car had such a battery, according to Car and Driver. The Hyundai Ioniq was the first modern production car to buck the trend, followed by the mechanically related Kia Niro. Instead of the 12-volt battery, Hyundai opted for a lithium-ion battery, which is located next to the main hybrid battery. If the starter battery dies, a switch inside the car, labeled "12V Batt Reset," pulls enough current from the main hybrid battery to jump the starter battery. In other words, the Ioniq and Niro are capable of jump-starting themselves, but they cannot be traditionally jump-started, nor can they be used to jump-start another car. In addition to the convenience, the lithium-ion starter battery is 26 pounds (nearly 12 kilograms) lighter than a regular 12-volt starter battery, which helps make these vehicles more efficient.

If you own a hybrid car, your best bet is to familiarize yourself with the jump-starting options and procedures for your make and model before you actually need them. Your owner's manual is always a good source for this kind of information. You also can contact your dealership's service department or the manufacturer's customer service. If you don't know what you're doing in an emergency, call a roadside assistance service (AAA is 1-800-HELP). That will keep you from getting hurt and help ensure you don't cause permanent damage to your hybrid car's complicated powertrain.

Can you jump-start an electric car? Here's what you can and can't do

You may not know that electric cars actually come with two batteries inside. Theres the large battery, which powers the motor and makes the car go, alongside a second smaller battery. The second battery powers the low-energy features such as lights, wipers and locks, and is essential to actually switching the car on.

In some high-end cars, the second battery is a smaller lithium-ion unit, but in a lot of cases youll open the hood to find a regular old 12-volt car battery the same kind youd find in a gasoline-powered car, complete with all the same limitations on how long it can hold a charge.

Right now, you might be wondering about the relationship between electric vehicles and jump-starting. Weve all had to jump-start our car at one point, or known someone who has, because those 12-volt car batteries are pretty finicky things.

Do EVs ever need jump-starting? Can you jump-start another car with an EV? The answer, unfortunately, is a little bit complicated.

Can you jump-start an EV?

Fortunately, in this instance, things are pretty simple. You can indeed jump-start an EV the same way you can with a gas-powered car. However, the chances of you ever having to do this are rare, thanks to the way the power system in an EV works.

Batteries in gas-powered cars 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 known for losing their charge fairly quickly, and if you dont intend to drive your car for a few weeks, it pays to switch on the engine for about 15 minutes every week to ensure the battery stays charged up.

If an EV uses a 12V battery, which the majority do, the battery will be identical to those found in other cars. However the smaller battery draws its power from the cars main power-train battery if its charge level dips too low.

Its important to remember that this borrowing of charge usually does not happen when the car is plugged in. If you leave an EV on zero-percent main battery for long enough, the 12V battery will eventually die too.

Whats more, in some cases having a dead 12V battery may prevent the main battery from being recharged. That is not a situation you want to find yourself in.

Its pretty rare for an EVs 12V battery to completely die, but it can happen. In those cases you can get a jump from another car, just as you would if your car still used gas. Or you can get a trickle charger to supply power more directly provided youre not in a hurry.

Should you ever need a jump-start, the process is exactly the same as if you were driving a gas car. Just make sure to unplug the car from a charger, because otherwise you risk causing damage to 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 cant transfer power to the larger lithium-ion battery that powers an electric cars wheels. The 12V battery is a lot less powerful than its bigger sibling and doesnt have anything close to what it takes to generate the motors that turn an electric cars wheels.

Trying to recoup lost range from a jump-start is entirely fruitless and a pretty dumb thing to attempt. One of the benefits of driving an electric car is the fact that it doesnt produce any pollution while you drive. Trying to use a gasoline engine to recharge the battery defeats the purpose and means you might as well be driving a hybrid.

If you need more range, you'll just have to find an EV charging station near you.

Can you use an EV to jump-start another car?

You can, technically, but that doesnt mean you should try to jump-start a gas-powered car from an electric or hybrid vehicle.

It is physically possible for an EV or hybrid to jump-start another car, although the process is a little different from the regular method. It can usually be accomplished by connecting both car batteries with a standard set of jumper cables and waiting for power to change hands. (In a regular jump-starting procedure between two gasoline engines, you would connect the negative clamp on the cables to a grounding point on the receiving car's frame, not to the receiving battery's negative pole.)

But you shouldnt actually do this, because it risks causing some significant damage to your car.

Why? It seems to be because of how EVs operate, 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 get the internal combustion engine physically moving quickly enough to achieve ignition.

EVs don't have an ignition circuit, because theres no physical fuel that needs igniting, and their 12V batteries lack that same kick. That means they dont have what it takes to jump-start the engine in another car.

Attempting a jump from an EV can put stress on its 12V battery, which isnt good for the battery itself. It can also confuse the battery-monitoring software, leading to unnecessary headaches down the road and potentially damaging the cars DC-to-DC converter.

The DC-to-DC converter is an essential part of an electric car, since thats how the 12V battery is able to draw power from the main battery, and 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.

Thats exactly why a lot of manufacturers specifically advise against using an EV to jump-start a gas-powered vehicle.

The Nissan Leafs owners manual features a warning that says LEAF cannot be used as a booster vehicle because it cannot supply enough power to start a gasoline engine. However, a gasoline engine vehicle can be used to jump start LEAF's 12-volt battery.

Meanwhile, the Tesla Model S handbook states that the car can not be used to jump-start another vehicle, and that doing so can result in damage to the Tesla. The manual also points out that using the car as a stationary power source, which a jump-start qualifies as, will void your 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 be happening to the 2022 Model 3 and Model Ys.

Both Nissan and Tesla, and plenty more, confirm that its perfectly safe for their electric cars to receive a jump from a gas-powered engine as long as the EVs are using regular 12V batteries. So dont let the fact your EV cant be used as a power source put you off.

Bottom Line

As different as EVs are from their gas counterparts, a lot of things are still 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 Teslas that have already fully switched to lithium-ion batteries.

If you have an EV, be sure to keep a pair 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 you can receive power, but you can't give it back.

Its unfortunate, but EV owners should be aware that these gestures of generosity will put your own vehicle 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 wont feel the same way.

For other car tips and tricks, check out our guide on how to drive in the snow and how to defrost a windshield without damaging it. You can also read and find out how you can keep your electric car's battery healthy.