Can You Jumpstart an EV?

Can You Jumpstart an EV?

First thing's first: Find the LV battery, which could be anywhere in the vehicle.

Here’s a real-world scenario: A customer brings their EV into your shop for service, and it’s been there for quite a while because the parts are on backorder. After a few weeks, you get in the vehicle to move it out of your way, and the ignition won’t turn on. It’s acting like the battery is dead, so what do you do now?

Chances are that the low voltage or LV, or 12V, battery inside that EV has gone dead. In most cases, the LV battery is not charged while the high voltage (HV) battery is plugged into the wall charger. So, even if your shop is outfitted with an HV wall charger, the LV battery could still go dead if it’s left alone long enough.

This scenario can present a few unique challenges to us as techs or shop owners. The first question we need to ask ourselves is, “Can I jump this EV with another car?” We would advise against this idea. It’s much safer to have a dedicated battery jumper, preferably one with some electronic assist to protect the system from surges, inverse polarity, etc. Compact battery jump packs are available and are really handy for all kinds of situations.

Now you need to find the LV battery, and it could be anywhere in the vehicle. This of course will vary from one EV to the next, but the most common locations would likely be under the hood or in the trunk. But, herein lies another challenge – some EVs, specifically Teslas, have electronic door poppers which release the trunk and the hood, AKA the front trunk or frunk. So, it sort of turns into a “chicken before the egg” situation. How can you open the hood to get to the LV battery and jump it, if there’s no 12V power to actually open the hood?

Fear not, because Tesla thought this one out. There is a pair of wires that are located just behind the front tow hook cover in the front bumper cover. With a 12V battery jump pack on hand, press firmly on the top right perimeter of the tow hook cover until it pivots inward, then gently pull the raised section out toward you. Pull the two wires out of the tow eye opening and connect them to the jump pack: red positive to red positive, black negative to black negative.

Be aware that these wires are not a charging point for the LV battery. Applying 12V power to these wires will only pop the hood release, but now you can gain access to the LV battery inside. Open the hood and remove the trim panel which covers the LV battery. Locate the positive charge/jump post, and connect a suitable battery charger or jump pack to it. Attach the negative cable from the charger/jump pack to the beam in front of the LV battery. You should now be able to charge or jump the LV battery, and power on the ignition.

You May Also Like

Matching OE Torque Specs When Reinstalling Is Important

Explore the key reasons as to why adhering to OE torque specs is crucial. This video is sponsored by TrakMotive.

CV axles transfer power from the transmission or differential to the wheels while also allowing for steering and suspension movement.  So matching torque specifications for CV (constant velocity) axles is crucial in ensuring proper installation and operation of the drivetrain.

Here's are key reasons why torquing CV axles to original OE specs is important:

EVgo Welcomes Scott Griffith to Board of Directors

Griffith previously served as the CEO of the Autonomous Vehicles and Mobility Businesses at Ford Motor Company.

Autel Releases the AC Elite G2 Charging Series 

The charger can be used in various settings, such as public commercial parking areas, residential areas, hospitals and service areas.

Branford Public Schools Award $60M Transportation Contract to Zum

Within five years, Zum will transition Branford to a 100% electric school bus fleet, the first in Connecticut.

Mullen Road Tests Solid-State Polymer Battery Pack

The results met or exceeded all requirements targeted for the first drive cycles for energy usage and driving range.

Other Posts

Turbocharger Maintenance ft. Rein TechSelect Turbo Kits

Learn about common challenges with turbocharger maintenance and how Rein TechSelect Turbo Kitsmake the repair process easier for technicians.

BendPak Founder Don Henthorn Passes Away

Grew company from small machine shop to global leader in car lifts and garage equipment.

The Standard® Advantage

Standard® knows that what comes out of a repair is directly dependent upon what goes into the box. This video is sponsored by Standard®.

Tesla Model 3 TPMS Service

Resetting and programming TPMS sensors for a Tesla is a lot like any other vehicle, and the challenge is still the same: keeping the light off.