One gotcha to add:
Remember to turn off the AVP between charging it at home and using it on the flight. You do this by "choking" it, i.e. pressing both buttons physical for ~10s, to bring up the "Power Off" dialog, so it's really not obvious.
I once had my AVP completely discharge between charging it one night, and wanting to use it on the flight <24h later. I'm guessing that the motion from the packing and trip to the airport was constantly waking it up, draining power.
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