The OP has a 2016 Leaf. From 2014 or 2015 on, there is no sign of the 12 volt charging issues seen with earlier Leafs. With no telematics "upgrade" to drain power and no known charging issues, what I originally wrote stands. I usually tell people to use a maintainer, but in the above case the very most that should be needed is fully charging the 12 volt battery with an external charger before parking it.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.