What You Need to Know About High-Voltage EV Systems

This MTD exclusive was provided by Craig Van Batenburg, MTD's monthly EV Intelligence columnist and owner of Van Batenburg's Garage Inc. dba Automotive Career Development Center, which provides training for facilities that service - or want to service - electric and hybrid vehicles.

If your technicians are not afraid of working on high-voltage systems, they are either extremely well-trained already or very naive.

Before they pick up a wrench and head over to any vehicle with a high-voltage system, it is imperative that they stay safe. You owe it to yourself and your co-workers to be sure high-voltage systems are understood, even if you do not work on the high-voltage side of things.

To do that, electricity must be part of every entry-level training program and that can be done online or in person.

Do you employ a master-level tech? Talk to them about taking on the technical training in-house. If you need to train someone who works for you, ask them if they are interested.           

If you have any doubts about an EV future in the automotive, heavy-duty truck or bus repair industry, just read the news. Now, you will see a lot of pushback and social media is full of anti-EV posts.

Some of the challenges are real, but many are not based on facts. We will not debate that in this column.

EVs are here, they are not going away and they need tires and related services. Your customers will turn to you for help. Are you ready? Your company’s policies will need to include basic electrical knowledge to help ensure the safety of your employees. The use of a volt meter and what it measures is a starting point — but not just any volt meter.

On the dial, it should be rated “CAT III @ 1000 volts.”  Those meters can safely test electrical systems of any voltage, from five volts to 1,000 volts.

To master the electrical side of EVs, it starts with the basics. Many books are out there about the basics and there are interactive online classes. ACDC, our company, works closely with repair shops and offers web classes for entry-level to master-level technicians.  

Do you know if your local high school or college offers auto service classes? If you don’t, time for a visit. Make sure you arrive with the mindset of “What can we do to help you?”

I am on two advisory boards for high schools in Boston, Mass., and Worcester, Mass.. It’s  worth my time. We all know that this industry must find new ways to support and train new employees. And we all need to do our part. Every year, more EVs will be sold and as they age, you will be asked to fix them. The basic work is the same on low-voltage and high-voltage, with the biggest difference being that high-voltage is lethal.

Never get lazy around any potential danger. To put this in perspective, gasoline is one of the most dangerous substances you will handle and each year, thousands of people worldwide die in gasoline-related incidents.

On Nov. 30, 2013, Roger Rodas and his friend and business partner, actor Paul Walker, who starred in the early “Fast and the Furious” movies, died while driving a Porsche. ACDC was working with Mr. Rodas at the time of his death.

It was not the crash that killed them, but the fuel used to drive the car as the vehicle caught fire.

Be aware of your surroundings and the risks inside your shop. Some jobs on this planet require putting your life at risk, but a high-voltage motor vehicle technician’s job is not one of them. Be safe. Gasoline — as well as high-voltage and hydrogen — all have risks.  

At this point, you might ask, “What have the original equipment manufacturers done to help protect EV technicians?”

For the safety of technicians, most OEMs use an interlock system.

If a tech removed something that has a high-voltage part near it, a signal to the HV battery computer will disconnect the HV battery by opening up two relays called “contactors.” At the same time, the HV capacitors discharge.

If an airbag deploys, the same thing happens as if the interlock was interrupted. The only exception to that is the Ford Escape HEV, model year 2005 to 2012, and its clones, the Mercury Mariner HEV and Mazda Tribute HEV. They use an “inertia switch” and that sends a signal to the HV battery computer when there is a crash — similar to an airbag sensor, but it only disconnects the HV battery and does not set off the airbags. At the same time, the HV capacitors discharge.

EVs and hybrid electric vehicles have a lot of safety checks and systems built into them. As with any new technology, play it safe! Read up on these vehicles before moving past a warning label. 

Remember — whatever you decide to do and at what level you want to move to with EVs is an internal conversation you need to have now. Doing nothing is not an option. This transition will take time, but don’t wait to act.

About the Author

Craig Van Batenburg

Craig Van Batenburg is MTD's monthly EV Intelligence columnist and the owner of Van Batenburg's Garage Inc. dba Automotive Career Development Center, which provides training for facilities that service - or want to service - electric and hybrid vehicles. For more information, see www.fixhybrid.com or email Craig at [email protected].