Hi offpist, thanks for sharing this awesome work.
I am currently off-grid using Outback charge controller and Inverter and an ancient 460Ah 48V Lead acid battery bank. These old batteries are a real worry.
Having swapped my 2011 Leaf's battery for a newer one http://www.mynissanleaf.com/viewtopic.php?f=51&t=21997&start=120
my plan is now to make a similar storage system to yours with the old pack. I will try not to ask too many stupid questions. Before I begin I want to know if you are still happy with your design or if there are some things you'd change, especially now that there are 2 year's worth of developments since your first build?