We had new 105Ah batteries, with confirmed capacity, 300W of panels on the roof and a new controller. We had connected the panels in series so they generated at 65V in full sunlight and that would minimise cable losses, and looked at the options that epSolar sold to go with their controllers.
First obvious addition was the MT50 display panel allowing the full range of metrics to be displayed as to how the panel was performing, and allowing optimal parameters to be set. This ran on a RS485 cable which looked like ethernet but had different connections and voltages. Lots of info on youtube