Contrary to what one might think, these electric trucks had a “cooling” or conditioning system. If one were to take a cursory glance with the trucks hood open, one could easily mistake a coolant reservoir container filled with antifreeze for a coolant recovery bottle on a traditional gas or diesel powered truck. The coolant reservoir bottle is part of an overall system to maintain a desired temperature for the battery and related hardware. If a driver needs heat in the cab, the power source is energy in the battery itself, and not from any cooling system. Remember the “hum” mentioned when standing next to an electric truck that is in operation? The hum is from the pumps circulating coolant around/through the battery and related hardware, as well as for the air compressor to maintain air pressure for the truck air brakes. The key point is that electric trucks have a cooling system to maintain the battery and related components at a near- optimum temperature. Cab heat, if used, does not come from the cooling fluid, so as not to have the battery temperature maintain system run at too low a temperature. Battery electric vehicles can operate at the same environmental ambient temperatures as today’s diesel engine products. Even though it was a winter day, the battery has a thermal management system that keeps operation at its best efficiency and effectiveness. Without the thermal management system, the battery would experience reduced performance and a shortened useful life.
During the short ride on the test track, we noted acceleration was brisk and cab noise essentially non-existent. There was no sense of excessive speed. When the engineer demonstrated the regeneration feature, it was obvious that it engaged. The sensation was as if the vehicle brakes were partially applied. At first, this seemed like a drawback to the system, but after the engineer explained a few things, it all made sense. The vehicle was designed this way to emulate the duty cycle of a yard spotter, which includes quick movement of a trailer from one spot to another —- accelerate, brake, and back into another spot and/or leave the trailer in another location.
Driver pre-trip inspections are critical to the safe operation of the commercial vehicle, regardless of their power source. Clearly, the specific items to be checked will differ for EVs, but are no more onerous. Fleets will need to ensure that the power system is operating within the specified tolerance range and has sufficient fluid with no leaks before it departs. Similarly, as with an ICE, the driver needs to be observant of warning signals and take appropriate action.
A final comment about N/V/H (engineering abbreviations for Noise, Vibration, and Harshness), things that a driver can hear, feel, and sense. In some ICE trucks, the driver or perhaps the maintenance department can set a diesel engine’s idle speed within limits. This adjustment is a way to stop the mirrors from shaking at idle. No such adjustment feature is required on the battery-powered trucks we drove. The mirrors were rock solid and the noise in the cab was nonexistent. When given a choice of ICE or EV in actual-use tests, drivers would take the electric vehicle, citing their quiet, smooth, and vibrationless operation.