Best practice to connect a separate load to the powerflo16

[skyking]

Hello, new guy here and ready to get the PV system going. We are building a new retirement home. This is my panel playground, it will have standing seam metal on there by the end of the week.

I am going with ATX's DC lighting implementation, and want to run it directly from the PowerFlo16 from the get-go.
The nominal voltage for the ATX Distribution Panel is 48~52V and they have connected direct to PV charged battery systems before.
I want to know the best practices for the battery end of things. I will start with a single 16, but may expand that depending on how it goes. The grid is coming to the property soon, but not sure when. I want to get something going so we have lights and basic functions.
It will be connected to the MN15-12KW AIO, of course 
Thanks for providing a forum for these things. I'll have lots of questions.