Using a fuel cell powertrain supplied by Ballard Power Systems, world leader in proton exchange membrane (PEM) fuel cell technology, FCV is hybridized with addition of a nickel metal–hydride battery pack and a brake-by-wire electro-hydraulic series regenerative braking system. The fuel cell engine converts chemical energy into electric energy using hydrogen fuel and oxygen from air. The electric energy then powers vehicle's electric drive motor, producing only water vapor and heat as by-products.

Just like Honda's Insight and Civic hybrids, new battery 'assists' main powerplant by adding extra power when accelerating or climbing hills, and is charged by regenerative braking system when braking or decelerating. Of course, Civic and Insight use a small gasoline internal combustion engine instead of a fuel cell, but principle is same.

“This Focus FCV is most sophisticated environmental vehicle Ford has developed,” said Dr. Gerhard Schmidt, Ford Motor Company vice president, Research and Advanced Engineering. “As such, is a critical success in our long-term strategy to move toward high volume production of hydrogen powered cars and trucks.”

The Focus FCV has onboard sensors, which constantly monitor fuel cell stack, trunk and passenger compartment. If trace amounts of hydrogen are detected, system will warn driver. If a slightly higher level is detected, system will transition to a limited operating strategy and then begin shutting down vehicle operations.

It features a powerful 42-volt lead-acid battery pack underneath rear seat, an auxiliary starter-generator between engine and transmission, an electronic control module, and a regenerative braking system, which charges battery while braking, and coasting.

With an auxiliary generator capability, truck's generator can operate when truck is parked without a key in ignition. The hybrid Chevrolet Silverado and GMC Sierra pickups could power tools or appliances for up to 32 hours non-stop. This design shuts engine down before tank is emptied, leaving enough gas to drive to a station for refueling. All power supply circuits are protected by a ground fault detection system to prevent overloads and short circuits.