He's being downvoted because that's completely irrelevant - the thing isn't relying on just coasting for millennia. That figure's based on the actual, measured

He's being downvoted because that's completely irrelevant - the thing isn't relying on just coasting for millennia. That figure's based on the actual, measured power draw of the motor, which includes the bearing friction and other drag, and dividing by the energy stored in the battery.