GetAll returns information about all batteries in the system.

Idle specifies a state where battery is in "capacity saving" mode.

Undefined specifies a state that was returned by the controller, but there is no platform agnostic mapping for it.

Unknown specifies a literal unknown state returned by the controller.

ErrNotFound Only ever returned wrapped in ErrFatal.

AgnosticState type enumerates possible battery states, using platform agnostic naming.