A dead electric car battery is a nightmare scenario for owners who are suddenly left stranded in a situation that might not have an easy solution. In addition to the big battery pack that powers the entire vehicle, all electric cars also have a standard 12-volt electric battery — just like a traditional automobile — that’s there to keep the electronics responsive and running while the EV is powered down. This is how remote door locks, lights and memory for the radio and seats function after you’ve parked your electric car.
The good news is, yes, you can jump-start a dead 12-volt battery in an EV in most cases. Here’s how.
Locate the 12-Volt Battery
The most difficult part of jump-starting a dead electric car battery is finding that battery in the first place. Not all EVs keep their 12-volt batteries under the hood like traditional cars. They could be located in the trunk, under the rear seat, under the rear cargo floor or elsewhere inside the cabin. The quickest way to locate the battery is to read the owner’s manual, as it will tell you exactly where it’s hiding.
It’s very important that you avoid any of the larger EV battery connections and cables during the jump-start process. These are identified by brightly colored cables and typically signage and stickers that let you know they’re attached to a high-voltage system. Don’t touch them, and do not attach alligator clips to them under any circumstances.
Connect the Cables
Align the vehicle you’re jump-starting with the one that has the working electrical system so that the batteries are close, but the cars aren’t touching. Then, with the power switch set to “OFF” in the EV, connect the jumper cables (see your owner’s manual for your vehicle’s exact procedure). Start the engine of the car doing the jump-start, and then turn the EV to “ON.” Once the vehicle is operating again, disconnect the jumper cables but keep it switched on for at least 20 minutes so the vehicle’s electrical system can charge the dead electric car battery enough to be useful once again.
Do Not Use an EV to Jump-Start an EV
One final word of warning: You won’t be able to jump-start an EV using a second EV. The 12-volt system on a given electric vehicle simply isn’t designed to provide this kind of service to a second EV, even if they are the same brand. Always use a gas-powered car or a portable jump-start device when dealing with a dead electric car battery.
Check out all of the batteries available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on dealing with a dead electric car battery, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photo courtesy of Wikimedia Commons.
Having been bitten by the car bug at a young age, I spent my formative years surrounded by Studebakers at car shows across Quebec and the northeastern United States. Over ten years of racing, restoring, and obsessing over automobiles lead me to balance science writing and automotive journalism full time. I currently contribute as an editor to several online and print automotive publications, and I also write and consult for the pharmaceutical and medical device industry.