My 940 watt of panels lead down to my Midnite controller @48 volts then to 12volts and into the back of my distibution panel, The heavy panel supply cables run it the 40ft to the engine room. I have 10xT105 Plus batteries. I previously had temp problems in the E.R. with high temps 130Degrees F and far to hot when I bought the boat. With upgraded ventalation ( discussed on another thread) I have lowered my temps to 90-110F and improved battery performance. The excess ventalation has enabled the engines to ingest 90F air (Ambient) which has enhanced output hp from the engines and efficiency.
The boat is in the Caribbean, so always fighting high temps in the engine room.