Next-generation lithium-ion battery developer Ener1 was awarded a phase II contract by the U.S. Defense Department to continue work on lightweight battery solutions for the UAV program. Under the $4 million contract, Ener1 will transition its battery development to batteries that provide UAV aircraft real-time tracking of military assets in harsh climates.

Ener1 says its EnerDel subsidiary, which previously was awarded $1.46 million under a phase I contract to support the UAV battery pack, will continue work on the phase II transition. Company officials say by the end of the phase II contract, UAV cruising time will increase from 53 to 81 minutes.

"The Department of Defense is one of the most demanding customers there is," Ulrik Grape, EnerDel chief executive officer, said in a statement.

"Our collaboration is pushing the capabilities of EnerDel's battery cell technology. We believe the market opportunities for developing advanced battery technologies for the military are substantial and will create research and development synergies with our core business of supplying complete systems solutions for the automotive industry."