05/13/2025

EV Safety Basics on the Shop Floor

Source: Body Shop Business

Electric vehicle (EV) safety — it’s a topic that’s on a lot of our minds. High voltage (HV) can be frightening because it can kill, but it shouldn’t scare you away. The reality is EV technology is a safe technology — as long as you understand it, respect it and follow established safety guidelines for EV service. Let’s look at how to establish safety basics in your shop.

OE Service Information

First and foremost, it’s critical to utilize OE service information and procedures for each and every hybrid or EV. There are two reasons for this. One — while there are standard service procedures and safety measures, which are going to be very similar between different makes, exact procedures will differ, and you simply need to follow them by the book to ensure absolute safety. The second reason is this technology is still evolving at a rapid rate, and our safety measures and procedures — as well as our tools and equipment — may also need to evolve over time.

When an EV comes into your shop, there are many services you can perform that don’t require the HV system to be disabled, including brakes, suspension, tires, certain types of steering repair, coolant changes and low-voltage electrical system repairs. But, if you’re ever in doubt, refer to the OE service information regardless of the service being performed.

High Voltage

Now let’s talk about HV. One of the first things we all learned was that brightly colored cables indicate they are carrying HV. There will be multiple cables on any EV because, in addition to the electric drive units, many EV systems utilize or distribute HV to a number of systems, including air conditioning, coolant heaters, steering power inverters, battery chargers and HV distribution modules. It’s important to remember that while orange is the most common color for HV cables, some manufacturers may use yellow or blue, but regardless, they are brightly colored, so they jump out to us as a warning no matter where they’re located on the vehicle when service to any of the HV systems is required. In addition to wearing the proper personal protective equipment (PPE), the HV system must be completely disabled and discharged. Every EV has a low-voltage battery that can be tested and serviced in the same manner we have used for many years.

Every EV also has a HV battery control module, as well as HV contacts or switches built into the battery. The HV powertrain control module (PCM), through low-voltage signals, determines when to open or close these internal HV battery contacts. This is very important because not only do these contacts open, for example, when the vehicle is switched off, but when the low-voltage battery is disconnected, they are also designed to default to an open state under the hood. You can also find a low-voltage service disconnect, which signals the body control module (BCM) to open these HV contacts. Some OEs utilize the service disconnect, some utilize scan tool commands in addition to the low-voltage service disconnect, and others call for disconnecting the low-voltage battery. But what if something doesn’t work correctly? There’s yet another safeguard. Every EV has an HV manual disconnect, which physically opens the HV circuit exiting the battery.

In the event the internal contacts do not properly disconnect, as you are following the OE procedures, which include a specified amount of time for capacitors to discharge, you will find specific instructions about when and where the proper PPE is required and when and where to check for voltage utilizing a live-dead-live test to ensure the HV system is disabled. Both these low-voltage and HV disconnects can be used by technicians as well as first responders on an accident scene to disable the HV systems. Additional disconnect procedures, often referred to as cut loops, offer first responders quick access to low-voltage harnesses that can be quickly cut, which again shuts down the HV system outside the battery. Keep in mind that even when disabled, HV is still present inside the battery pack. Following the proper disconnect procedures — along with confirming the system is completely disabled — and using the proper electrical equipment is absolute assurance that the HV system is now safe to work on. 

Personal Protective Equipment

Staying safe while working on an EV requires the correct shop equipment as well as the correct PPE, and shortcuts are simply not an option. Let’s take a look at everything you’re going to need.

We’ll start with PPE and electrical safety gloves. Class zero electrical insulating gloves rated for 1,000 volts are required for EV service. Simply put, these gloves prevent HV from traveling through your hands, and they must be tested every time you use them by checking for a pinhole or any damage that could allow voltage to pass through a glove. An insulator is the most efficient way to do this. Insulating gloves must also be clean and dry so there are no conductive substances that can allow HV to travel outside the glove to your arm. Treat these safety gloves with extreme care. They can be damaged easily and are sensitive to UV rays, so they should be stored in a dark, dry environment. A ventilated, UV-resistant bag is the best option. Safety gloves must also be re-certified every six months. You’ll also wear them with a leather outer glove to protect them; most prefer to wear an inner cotton glove as a liner to allow your hands to breathe.

In addition to gloves, safety glasses and face shields are recommended, as is clothing that doesn’t combust easily, such as cotton. Footwear rated for electrical hazards is also recommended, as it won’t allow electricity to travel through the work area where the vehicle is located. The work area must be clearly marked and cordoned off with bright safety cones or stands and tape to warn everyone that work is taking place on the HV system. It’s also required to have a safety hook, also called a rescue hook. So, in the event a technician comes into contact with HV, another technician is able to use the hook to physically pull the victim away from the vehicle. For this reason, it’s recommended that two people are present anytime work is being performed on the HV system of an EV.

Multimeter

A category three-rated multimeter and test leads are required for testing high voltages of these levels. A meter that isn’t rated to handle HV poses the risk of arc flash explosion or transfer of HV. As we’re talking about multimeters, a milli meter is required for testing some circuits due to the increased accuracy required, and a meter sometimes referred to as an insulation meter is required to check for insulation faults within the drive motor or cables.

Approving the meter is another requirement. When performing a live-dead-live test, you use it to check the operation of your multimeter at the voltage for which you’re testing. Then, after confirming the HV circuits are disabled, you use it to recheck your meter to make sure it still reads and works properly. Nonconductive tools, of which there are two different types, insulated or composite, are required for some procedures where the possibility of contacting a live circuit exists. Insulated tools are standard tools with a nonconductive coating. Composite tools are made of strong, durable, nonconductive composite materials. Many companies offer a number of wrenches, screwdrivers, flyers, ratchets, sockets and extensions of one type or the other. EV technology is a safe technology; as long as you follow the EV guidelines for testing and disabling the HV circuits when necessary, an EV is as safe to work on as any other vehicle on the road. However, you’re absolutely going to have to use the proper PPE, and you’ll need these insulated tools as well.

That being said, when you’re working on one of the electrical systems after the HV circuit has been disabled, your regular hand tools are fine. At this point, many people perceive an endless struggle with large, bulky gloves and tools that look like children’s toys. That’s not the case. Once the HV system is disabled, the danger is gone.

Lifting Equipment

Now that you’ve got a handle on the HV testing, we can look at lifting equipment. Using the proper ALI-certified vehicle lift is critical. It must be rated to handle the additional weight of an EV, and the lift arms must retract and extend far enough to safely engage the manufacturer’s recommended lifting points on EVs. These points are often on the side rails or frame rails right next to the battery pack, making it imperative that the lift adapters are placed precisely for your safety and to prevent damage to the battery.

Your lift should have a strong swing arm restraint system to keep the arms in position during service. The lift arms and swing arm restraints as well as adjustable lift adapters are critical in this situation, because you’ll be lifting the vehicle on the edge of the pinch welds. To clear the battery, you must make sure to have good, solid engagement of the lift pads and that the arms will not move. Some vehicle manufacturers have different lifting points for servicing the HV batteries than for performing routine maintenance. These may require special adapters as well. Check the vehicle service manual to be sure when it’s time to remove the battery. You’ll need a battery lift table that’s suited for the job. Think about this — an EV battery can weigh from 1,000 to well over 2,000 pounds On top of that, all battery packs may be equally balanced.

Not only must a lifting table be able to support the battery’s weight, but it must do so while offering the stability to handle a potentially unbalanced battery while allowing you to roll it out from underneath the vehicle. The weight alone is a factor, but just as important is not damaging the battery in any way. Physical damage from dropping a battery or even seemingly minor damage from improper lifting can cause internal short circuits, which can cause a fire. In some cases, it may take 12 to 15 hours for the fire to start. When installing a battery, the lift table is equally important so you can align the battery pack properly without damaging electrical connections or yourself.

Summary

PPE shortcuts are not an option. Equipment shortcuts are not an option. Using the proper equipment for vehicle lifting and battery removal can prevent battery damage and accidents.