I just took delivery of a 740b from Aircraft Spruce, had to do the battery switch cycle thing as described above out of the box. Let it charge all day, unplugged it from the wall charger, it booted up just fine on battery power. Battery icon indicated full charge. Shut it down, took it out to the hangar to design my panel mount. Tried to boot it up on battery power. Nothing. Cycled the battery switch again with a pick from my toolbox, then it booted up OK. Battery icon still depicted a full charge. Does the 740b require a battery switch cycle before every battery-powered boot?