UK-based aircraft components-to-energy conglomerate Meggitt has confirmed that the Boeing 787’s battery charger, made by one of its US subsidiaries, has passed a series of tests by the National Transportation Safety Board (NTSB).

The tests were performed on the battery charger produced by Meggitt subsidiary Securaplane at its Tucson, Ariz. facility in January.

The NTSB said, “The acceptance test procedure of the APU battery charging unit was conducted at Securaplane in Tucson, Ariz., on Jan. 21. The battery charging unit passed all significant tests and no anomalies were detected.”

The 787’s lithium ion battery system is at the center of the investigation into the Jan. 7 Japan Air Lines fire at Boston’s Logan International Airport. A further incident involving an All Nippon Airways 787 later that month led to an emergency landing. The 50 787s in service have since been grounded.

Meggitt’s financial director Stephen Young was quoted by Reuters as saying: “Our products have been through a lot of tests, including the two damaged units from the fires, and they both re-passed all the required tests. The unit is doing what it is supposed to do.”