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Can You Jump-Start a Dead EV Car Battery?

Jumper cables for a car

If you recently bought an electric car or are in the market for one, a common question is “can I jump-start a dead EV car battery?” No one wants to get stranded with a dead battery and a car that won’t “start,” so it’s a valid concern.

Electric vehicles have a large high-voltage battery pack that gives power to the motors instead of a gas engine, and that’s not what we’re talking about here. You cannot “jump-start” the massive battery inside an EV. However, that’s not the only battery in an EV.

Can You Jump-Start an Electric Vehicle?

Aside from the huge high-voltage battery pack, EVs have a second electrical system that employs the same 12-volt batteries as gas vehicles to power the lights, door locks, computers, and other essentials.

Similar to any regular car, that 12-volt battery can lose its charge and prevent the vehicle from turning on. So if you leave a door cracked or the dome light on overnight, that battery could be dead in the morning, and you’ll hear that dreaded tick-tick-tickkkkk sound.

The answer is yes. Yes, you can jump-start this battery on your EV in the same fashion as any regular gas-powered vehicle. That said, there are a few things you’ll want to know first.

Tips Before You Jump-Start an EV

Tesla Model S parked next to a line of Superchargers
Grisha Bruev/Shutterstock.com

Obviously, jump-starting the battery on an EV is a little bit more complicated than your average vehicle. That’s because the 12-bolt battery isn’t always in the same location, plus there are dangerous high-voltage systems you’ll want to avoid altogether. Here are a few safety concerns you’ll want to keep in mind, according to KBB.

  • Never try to jump-start the high-voltage lithium battery in an EV.
  • Do not use another electric vehicle (EV) to jump-start your EV’s 12-volt battery.
  • Use eye and hand protection with safety glasses and gloves.
  • Do not jump-start the 12-volt battery while charging the bigger EV lithium-ion battery. (Unplug it from the wall or a charging station)
  • Make sure the EV is off and in “Park.”
  • If you’re nervous, it’s best to call for help.

Never mess with the high-voltage battery system that makes your electric car move. Those systems have insane amounts of power and can cause harm to yourself, others, or the vehicle. Additionally, do not use another EV for the jump, and instead, look for a gas vehicle.

As more electric vehicles get released, this could be hard, but it’s something to keep in mind. Another option is to buy and use a portable jump-start device.

Finding the 12-Volt Battery

On most gas-powered vehicles the 12V battery is located under the hood. However, some cars may have it under a wheel well, floorboard, or even in the trunk. This can be an even bigger problem when it comes to electric vehicles.

Many vehicles still put the battery upfront, but it’s best to check your owner’s manual to find where the 12-volt battery is located on an EV.

For example, on most newer Tesla’s, the small 12-volt battery is located under the hood and behind the frunk (the front trunk) near the windshield. So you’ll have to open the frunk, pull up some trim pieces, and you’ll see the typical 12-bolt battery and its terminals where you’ll place jumper cables.

How to Jump-Start an EV?

For the most part, jump-starting an EV is similar to jumping any other car. You’ll want to position both vehicles close together, make sure they’re in park, turn off lights or any accessories, then get ready.

First, connect the positive red cable to the dead EV’s positive (+) terminal, then connect the other end of the positive red cable to the positive (+) terminal on the helper vehicle. Now, connect the negative black cable to the helper vehicle’s (—) terminal. Next, connect the other end of the negative cable to a grounding point on the dead EV. You do not connect it to the discharged battery’s negative (—) terminal.

From here, start the car and engine on the helper vehicle and give it a second, then start or “turn on” the EV, and you’re all set.

And as we said earlier, if you’re uncomfortable with any of this, it’s best to call for help or roadside assistance.

Cory Gunther Cory Gunther
Cory Gunther has been writing about phones, Android, cars, and technology in general for over a decade. He's a staff writer for Review Geek covering roundups, EVs, and news. He's previously written for GottaBeMobile, SlashGear, AndroidCentral, and InputMag, and he's written over 9,000 articles. Read Full Bio »