EV and Hybrid Service - Safety First

Maintenance Guidelines and Safety Measures

Maintenance requirements for plug-in hybrid electric vehicles (PHEVs) and hybrid electric vehicles (HEVs) are in many ways like those for internal combustion vehicles, but the up and coming all-electric vehicles (EVs) require less maintenance overall. Manufacturers are designing these vehicles and developing guidelines with maintenance and safety in conjunction. Electric and hybrid vehicles present a number of service opportunities (many unrelated to the EV power train) but before you commit, understand the potential hazards of dealing with electric vehicles. The largest concerns focus on the potential energy hazard of lithium-ion batteries and high voltage wires.  Manufacturers have worked to address safety questions centering on self-contained systems that prevent leakage or other compromises to the system.

EVs, PHEVs, and HEVs have high-voltage electrical systems that typically range from 100 to 600 volts. Their battery packs are encased in sealed shells and meet testing standards that subject batteries to conditions such as overcharge, vibration, extreme temperatures, short circuit, humidity, fire, collision, and water immersion. Manufacturers design these vehicles with insulated high-voltage lines and safety features that deactivate the electrical system when they detect a collision or short circuit.

A striking pastel orange (sometimes referred to as eOrange) is a popular method for identifying plastic-sheathed, high-voltage, current-carrying components. Most suppliers manufacture eOrange with material that retains its bright color warning effect without darkening, even after 1,000 hours of service. All bright orange cables are high voltage, but not all high voltage cables are orange. Some could be light blue or yellow, but today most auto EV/hybrid manufacturers use orange.

Besides high voltage concerns, most electrical vehicles now implement an indirect liquid cooling system to control the temperature of the battery pack. This system is much like the conventional internal combustion engine cooling setup with water ethylene glycol as the base formula. Low-range EV’s and hybrids had been able to cool the battery packs via air-cooled methods, but the extreme heat produced by longer range EV’s require cooling with liquid, which is more effective. The same precautions in dealing with glycol based coolant in internal combustion vehicles should be used in the liquid cooling system in electric vehicles. Check the manufacturer’s recommendation for cooling battery pack intervals.

Even if you are not addressing the drive/power train, there are service opportunities that are found on the rest of the vehicle for any shop:

Brakes – Electric vehicles introduced a new type of principle braking system… regenerative braking. When you take your foot off the accelerator pedal, the regenerative braking system kicks in to automatically charge the EV’s battery while slowing the vehicle. An EV still has a traditional friction brake system—meaning it has brake rotors, brake calipers, pads or shoes, a master cylinder, and hydraulic DOT-spec brake fluid. The regenerative brakes take care of most of the braking, but the conventional braking system works as a secondary to come to a complete stop.

The EV regenerative braking function relies on the electric motor’s resistance to slow down the vehicle, therefore wear on pads is reduced and the life of the pads lengthened. Be aware though, with less action by the brakes the calipers will not be used as often and an annual brake inspection is recommended by most manufacturers. The inspection should include lubrication of the moving caliper surfaces to help avoid calipers sticking, this is more likely because the calipers are not used as frequently. Also, some manufacturers recommend a brake flush for EV’s every two years… another opportunity, so check their recommendations.

Tires and Alignment – Some manufacturers use a tire with a foam lining on the inside of the tire to help prevent road noise. The foam helps dampen the sound coming from the tires which they found can be more noticeable with the quiet ride of an electric vehicle, even at slower speeds. The foam-lined tires can cost $20 to $40 more per tire than the same standard tire. If a customer returns complaining of road noise they had not noticed previously, they may have replaced the foam lined with a standard tire. Since the foam liner is bonded to the tire, it does not affect the balancing service. Alignment is serviced using the same equipment and procedures as in the past.

Cabin Air Filters – Many suggest replacement once a year and the service is usually the same as that of a conventional vehicle. This is one of the few filters that an EV will need to be serviced on a regular basis.

Windshield Wipers – Another maintenance item that does not change from the conventional internal combustion vehicle. There may be different connectors, but it seems like every year a new connector hits the market for all vehicles. Also, windshield washer fluid level should be part of every inspection.

Lighting – This is a service where replacement procedures will not change but frequency will. Most (not all) of the lights on an electric vehicle are LED’s which draw a lot less current and last a lot longer. The same style bulbs that have been used in the past are being replaced by many in an LED configuration.

Battery – Until the technician completes a safety training course, the only battery that should be serviced is the one in the key fob!

For those who wish to service the power train of electric vehicles and want to ensure safety even during routine maintenance, SAE offers a one-day live on line course titled: Fundamentals of High Voltage xEV, Safety, and PPE.

They describe the course as: This one-day course explains EV safety fundamentals, including personal protective equipment (PPE) and how to develop and establish common safety procedures for working around high-voltage vehicles.