Further to my last question on air travel, we are travelling to LA and are plugging in to power for the flight. From LA we fly to Miami with Delta, we have to use battery power. FAA policy is that we need 150% battery life which will be 3 batteries. Delta are telling us we need 7 batteries which makes no sense. Their reasoning is we need to take enough for return flight, which is 2 weeks later. Our carrier from Brisbane to LA will not let us take anymore than 4 batteries. Has anyone had experience with this ? We leave Brisbane on Wednesday 28th January.