Seattle Times is reporting that Boeing had numerous reliability issues with the main batteries on its 787 Dreamliner long before the two battery incidents this month grounded the entire 787 fleet.
More than 100 of the lithium-ion batteries have failed and had to be returned to the Japanese manufacturer, according to a person inside the Boeing 787 program with direct knowledge.
The frequency of battery failures reflects issues with the design of the electrical system around the battery, said the person on the 787 program. Most of the batteries were returned because they had run down so far that a low-voltage cutout was activated. At that stage, the batteries, which cost about $16,000 each, are essentially dead and cannot be recharged. For airline operators, such failures could be costly in terms of airplane downtime and inconvenience.
These problems seem separate from the two more significant incidents, when a battery caught fire on the ground in Boston and another smoldered in midair in Japan, forcing an emergency landing. But the electrical system that monitors and controls the batteries is under scrutiny as they probe the cause of the recent incidents.