A propulsion
system (20) for an aircraft (1000) includes a battery (64), an electrical
distribution system (66), a first
control channel (110, 114), and a second
control channel (112, 116). The battery (64) includes a plurality of battery strings (72). The electrical
distribution system (66) includes at least one string
contactor (132, 142) for each of the plurality of battery strings (72). The at least one string
contactor (132, 142) includes a first gate (138, 148) connected to the first
control channel (110, 114) and a second gate (140, 150) connected to the second control channel (112, 116). The at least one string
contactor (132, 142) is operable to a closed position with a first
control signal present at the first gate (138, 148) and a second
control signal present at the second gate (140, 150). The at least one string contactor (132, 142) is operable to an open position with one or both of the first
control signal absent at the first gate (138, 148) or the second control
signal absent at the second gate (140, 150).