I am in the process of wiring up my 100/20 mppt controller to a deep cycle battery, 3 x 80watt PV wired in series and a fuse box which will power my accessories including a fridge. I presume I’m correct in thinking that my battery will charge my accessories through the controller when the solar is insufficient? Also do I need to send the ground wire back to the controller from the fuse box or can I ground directly back to the battery? Thank you