The batteries and chargers are modified by their respective manufacturers.
The modified batteries and chargers are then installed onto the aircraft.
What the B787 Battery Looks Like
Inside are 8 small batteries (cells),
the Battery Monitoring Unit (BMU),
and other components.
Battery Modification Points
Battery Case Modification Points
In addition, the battery and cell manufacturing/testing processes have been enhanced.
Battery Charger Modification Points
In order to reduce the burden on the battery cells (to prevent short circuits, etc.), the charging and discharging processes have been revised.
The enclosure shown below will be newly installed together with a new vent line.
This stainless steel enclosure will completely enclose the blue battery case. In the event that a battery malfunction occurs, the enclosure will contain it so that other aircraft systems will not be affected.
A pressure release disc is installed at the back of the enclosure. When the difference in internal and external pressure of the enclosure becomes greater than 15-18psi (pounds per square inch), the disc will open to enable smoke, etc. to be vented overboard through the vent line.