Remember batteries don't discharge in a linear curve (NiMH, Alkaline, etc)

https://www.google.com/search?client=firefox-b-1-e&biw=1232&bih=674&tbm=isch&sxsrf=ACYBGNR7JDkMv0u1Wa-V91k5ZuG2eo1xZg%3A1578924657991&sa=1&ei=cXocXq2QPIbr_Qaqq7v4DQ&q=eneloop+discharge+curve&oq=eneloop+discharge+curve&gs_l=img.3..0j0i7i30.9817.12291..12592...0.0..0.836.2439.1j7j5-1j1......0....1..gws-wiz-img.......35i39j0i5i30.eMHVbnejgxY&ved=0ahUKEwjtjPfa4IDnAhWGdd8KHarVDt8Q4dUDCAY&uact=5

The self discharge curve is similar, the Eneloop will loose a decent amount right at first then the discharge will taper off. So after 4 months you might have 90% capacity and then after 12 months it will be 89%.

The other issue I run into is a lot of newer devices will still draw some current even when off for the soft on, or internal close, or internal settings. My old Garmin GPS I've learned to top off the batteries once a month for example.