I've had my refurb MBA 11.6 now for about two weeks. I've calibrated my battery twice in that time (run on battery until the MBA shuts down, let it sit for 6+ hours and then charge it completely) and my battery had never gotten above 98% when fully charged.
I realize it is just being nit-picky, but I would like it to reach 100% as well when fully charged. I will try juro's recommendation above and see if that works for me.