Originally Posted by
number_6
One problem is that rated battery life is shorter than some QF flight durations

And you can't use external batteries or swap batteries on an iPad.
There are a few third-party cases with inbuilt battery packs - Jetstar's using one for their iPad-as-IFE rollout (although I don't see that the idea is for the QF iPads to be used
all the time during flight).