The motor controller monitors the motor’s position, speed, power consumption and temperature. Using this information and the throttle command from the driver, the motor controller and inverter convert the DC voltage supplied by the battery to three precisely timed signals used to drive the motor.
The high-voltage air-conditioning system is specifically designed for electric-vehicle applications, drawing electrical energy directly from the main battery pack.
The electric-drive water pump circulates coolant for the traction motor, inverters, battery and climate-control system.
The traction motor performs the conversion between electrical and mechanical power. Electric motors have efficiencies three times higher than that of a standard gasoline engine, minimizing energy loss and heat generation.
An electro-hydraulic steering pump was installed to assist a retuned steering rack. It is tuned to deliver the same driving dynamics as the gasoline-powered Focus.
The transmission has the identical role as in a conventional gasoline-powered vehicle; however, it has different design considerations due to the higher RPM range available from the electric motor and the increased emphasis on efficient and silent operation. The transmission is a single-speed unit.
More than 95 percent of the energy normally lost through braking can be recovered and stored in the battery.
The vacuum pump provides energy-efficient power-assisted braking.
Heating systems are specifically designed for electric vehicle applications using energy-efficient technology to heat the coolant that circulates to the passenger car heater. Heat also may be circulated to the battery to optimize performance.
The powertrain control module monitors and controls each vehicle system, and manages the energy and mechanical power being delivered to the wheels to maximize range.
The battery pack is made up of 86 cells for a total of 23 kWh of power. The batteries are liquid cooled. The pack includes an electronic monitoring system that manages the temperature and state of charge of each of the cells.
Power electronics are used to convert the off-vehicle AC source from the electrical grid to the DC voltage required by the battery, thus charging the battery to its full state of charge in a matter of hours. The current charger is air cooled. The production design will accommodate both 110 and 220 voltage sources.
A DC-DC converter allows the vehicle’s main battery pack to charge the on-board 12V battery, which powers the vehicle’s various accessories, headlights and so forth.
A standard SAE J1772 plug interface is used for charging. Ford’s charge port “light ring” provides an external indicator of charging status.