Originally Posted by
FTstudent
The thing that puzzles me the most is changing the order of plugging in the individual pieces of my Nexus 7 makes a difference. Everything connected and working on ground power. Then power comes back on at 10,000 and tablet is not charging. Unplug. Light goes green. Plug back in, green light goes off and no charging. So then unplug the cable from tablet. Plug in the adapter to the outlet. Next connect power cable to device, and now it's working. sUA plugs seem more finicky and location is terrible for the plug/unplug game.
Part of this is likely the turn-on charging surge of the power adapter. Power adapters when power is first applied look essentially like a short circuit for a short time. Once the AD to DC convertor is "charged up" then the current draw is normal. In a system with a low current level circuit "breaker" (like they are on plane) and fast response, the protection circuit may kick in. Unplug / reconnect will reset the protection circuit and because the power module will stay partially charged, the retry turn-on surge then will be much lower. Might take a couple of tries if not done quickly. The dynamics of this is very depending on the circuit protection and the power module and the device connected.