The PMS inside GT40 compares the external and internal battery level 600 times per minute to decide wether it is safe to feed power into your board. It powers the GT40 up once it detects your board is turned on, and it automatically powers off as your board is turned off or sleeps.
Spacecraft level Aluminum, heat treated to T6, coated with a thin layer of polycarbonate to create an insulatve inner wall to fit the battery cells and a super durable surface. The structure has been revisioned 3 times, and we settled on this 2 structural wall design to ensure it has perfect strength.