Though hybrid vehicles have been around for some years, each year new variations are introduced. In some hybrid electric vehicles, a small gas engine produces the electricity, which drives the vehicle. In others, an electric motor assists the gas engine, which propels the vehicle. There are plug-in hybrids; they can be plugged in at home or at public charging stations (though there are not very many of these yet) to charge the high voltage battery, thus giving the vehicle a longer range and much better gas mileage. (Some claim over 100 miles per gallon.) There are pickups and trucks with electric-assisted transmissions, and also full electric vehicles (without any gas engines to charge the batteries), and even high performing, high speed full electric sports cars.
In short, there is a staggering array of electric vehicles (EV) and hybrid electric vehicles (HEV) that collision repair technicians will encounter. The good news is that the skills needed to repair the bodies and frames of such vehicles are not much different than those needed to repair any other vehicles, though new types of equipment must be checked. The bad news is that EV and HEV
repair can be a very dangerous, even life-threating workplace environment if proper precautions are not taken. High voltage batteries (300 volt or more, depending on the vehicle) can kill a technician who has not disarmed the high voltage system properly. Regenerative breaking systems, even with the battery disconnected, can produce enough electricity to injure a tech, just by his or her pushing the disabled vehicle around the shop. Heat from the booth can damage or reduce the life expectancy of a high voltage battery if the manufacturer recommendations are not followed. Even the equipment that keeps us safe as we disarm a high voltage (HV) battery must be tested and handled properly, or it may fail.
High voltage PPE
As technicians, we are familiar with personal protective equipment (PPE), such as glasses, gloves and respirators; but with HEVs and EVs, the PPE gloves take on a new dimension of importance. First needed, and possibly most important, is a set of rubber-insulated lineman’s gloves. The gloves should be rated at 1000V AC (class 0) (Fig 1) and tested before each use. Some simple but vital cautions should be
observed when using lineman’s gloves. Because they are rubber and they will be used around metal, they could become damaged, and even a pinhole could allow high voltage in. Before they are used, they should be checked for leaks by rolling them up from the cuff and inflating them (Fig 2). Also, if they get wet or your hands are damp when using them, they may not provide the protection that is needed. I have even seen a recommendation that a second pair of work gloves be worn over the lineman’s gloves to protect them from damage while in use (Fig 3).