EaglePicher Technologies expects to certify a lithium-ion main-ship aircraft battery by year-end, according to Ron Nowlin, vice president and general manager of EaglePicher Aerospace Systems. The battery has been selected for a jet, but Nowlin was unable to reveal the OEM and said he “cannot confirm” news reports “that we are doing any work for Cessna.”
The battery chemistry is lithium-iron phosphate, which, he said, “is a little more thermally stable” than the lithium-ion cobalt technology used in the Boeing 787 battery. The EaglePicher aircraft battery weighs 40 percent less than a comparable Ni-cad battery and is housed in a stainless steel container with a top-mounted heat sink to keep it cooler during the charge cycle.
The battery management has redundant electronics systems, but if both systems should fail then the battery must withstand an explosion containment test to meet the applicable DO-311 performance standards. “This requires you to charge a cell in the pack to the point that it ruptures or vents,” Nowlin said. “And you have to ignite the electrolyte. It can’t release flame, electrolyte or particles outside the battery enclosure.” EaglePicher’s battery has passed initial DO-311 tests and will be subjected to further testing with validation by an FAA DER before certification.