Can you revive a dead EV car battery? – Geek Review

Jumper cables for a car

If you recently purchased an electric car or are looking for an electric car, a common question is “can I jumpstart a dead EV car battery?” No one wants to be stuck with a dead battery and a car that won’t “start”, so this is a valid concern.

Electric vehicles have a large, high-voltage battery that powers the motors instead of a gasoline engine, and that’s not what we’re talking about here. You can’t “jump start” the huge battery inside an electric vehicle. However, that’s not the only battery in an EV.

Can you revive an electric vehicle?

Besides the huge high-voltage battery, electric vehicles have a second electrical system that uses the same 12-volt batteries as gas-powered vehicles to power lights, door locks, computers and other essentials.

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

The answer is yes. Yes, you can jump start this battery on your electric vehicle the same way as any regular gasoline vehicle. That said, there are a few things you’ll want to know first.

Advice before starting an EV

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

Obviously, jump starting the battery of an electric vehicle is a little more complicated than that of an average vehicle. That’s because the 12-bolt battery isn’t always in the same place, and there are some dangerous high-voltage systems that you’ll want to avoid altogether. Here are some security issues you’ll want to keep in mind, according to KBB.

  • Never attempt to jump start the high voltage lithium battery of an electric vehicle.
  • 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 larger EV lithium-ion battery. (Unplug it from the wall or a charging station)
  • Make sure mobility device is turned off and “parked”.
  • If you’re nervous, it’s best to call for help.

Never mess with the high voltage battery system that powers your electric car. These systems have insane power and can cause harm to you, others, or the vehicle. Also, don’t use another electric vehicle for the jump and look for a gasoline-powered vehicle instead.

As more EVs come out, that might be tricky, but it’s something to keep in mind. Another option is to purchase and use a portable starter device.

Find the 12 volt battery

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

Many vehicles still place the battery in the front, but it’s best to check your owner’s manual to find out where the 12-volt battery is on an electric vehicle.

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

How to start an EV?

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

First connect the positive red cable to the positive (+) terminal of the dead electric vehicle, then connect the other end of the positive red cable to the positive (+) terminal of the assist vehicle. Now connect the negative black cable to the (—) terminal of the support vehicle. Then connect the other end of the negative cable to a ground point on the dead EV. You do not connect it to the negative (—) terminal of the discharged battery.

From there, start the car and support vehicle engine and give it a second, then start or “ignite” the EV, and you’re good to go.

And like we said earlier, if you’re not comfortable with any of this, it’s best to call for help or roadside assistance.