My leaf is 2012, bought last year, unsure if the battery checks were done while under the previous lease owner. I have till 12/2017 for the warranty, and am currently at 10 bars (waiting on my OBDII dongle to check leafspy stats). Since it seems there is a possibility of dropping two more bars, I'm going in for the batter checkup and wanted to share quotes.
As a data point, Hanlees Hilltop Nissan in Richmond, CA wants $160 for a battery check. I confirmed there are no other services besides battery check in this quote. They are crazy. Nissan Marin gave quoted $77, and Autocom Nissan of Concord quoted $45. The highest was > 3.5x the price of the lowest! But the good news is that it is possible to get reasonable and insane prices in the san francisco bay area, so call around first.