Another of Ener1's subsidiaries is EnerFuel, a company focused on fuel cells. CEO Charles Gassenheimer said on the call that EnerFuel is making significant progress in development of its high temperature fuel cell. The stack is being developed primarily for use as a range extender. Several automakers have shown and tested concepts based on fuel cell extended range EVs, including General Motors and Ford.
Daniel Betts, EnerFuel's Principle Engineer, said on the call that the company's stack has been installed into an ER-EV and has been tested since December 2008. The complete fuel cell system consisting of stack, hydrogen storage and electronics weighs 176 pounds and adds 20 kWh of energy to the existing battery system. Using the fuel cell as a range extender for a plug-in vehicle allows it to be run at constant output, greatly increasing its efficiency as compared to using it as the primary power source. The EnerFuel stacks are being developed for an output of 3-15 kW, enough to maintain and extend battery range.