An apparatus and system for mounting, monitoring, and managing one or more battery packs within a housing attached to or, integrated in, a commercial vehicle such as a semi-trailer for the purpose of providing battery power to all-electric powered commercial vehicles. One or more removable battery packs of various sizes may be mounted in one or more housings within an assembly installed on, or included as a structural part of, the frame of a commercial vehicle. Electrical connections on the installed battery packs connect the battery packs to each other and to the commercial vehicle electric motors. Computer systems permit the monitoring and managing of each installed battery pack. Thus, commercial vehicles may be provided with the appropriate battery power supply for an anticipated trip, without being required to purchase or to haul excess batteries and thus excess weight on the trip.

An auxiliary power system for an electric semi-truck is disclosed. The auxiliary power system includes a power storage device mounted to a semi-trailer. One or more main batteries provide propulsion to a semi-truck and are in electrical communication with the power storage device to receive auxiliary power therefrom. The power storage device is operable to increase the range over which the semi-truck travels between recharging. The power storage device may be configured to either provide supplemental power to increase the power output of the semi-truck in real-time or may be configured to increase the range between recharging of the main batteries of the semi-truck.

A trailer, in particular a utility trailer, for road vehicles on which an extendable current collector or an electrical contact element for an inverted current collector is placed.

A motorized supplemental trailer axle includes an axle securable to a trailer and having a wheel affixed to opposing ends thereof. A motor for powering the axle wheels is operably connected to a battery power supply. A transfer case having a clutch mechanism is operably connected to the motor and the axle, wherein the clutch mechanism is configured to selectively engage the motor with the axle to rotate the pair of wheels. A control module includes a sensor configured to monitor rotational speed of the pair of axle wheels, a processor, a non-transitory computer readable medium operatively connected to the processor, and a logic that, when executed by the processor, causes the system to calculate a wheel speed of a vehicle currently towing the trailer and activate the motor to rotate the wheels of the trailer axle at a speed that matches the towing vehicle's wheel speed.