Why do I have this extra electrical box?

[SolitudeAtLast]

[howson]

howson, I'm going to play devil's advocate here. Since the subpanel isn't coming with residential, but it is with the solar option, wouldn't including it as part of the "Solar Package" be the same as the larger radiator being included in the "Towing Package" of a truck?

If the sub-panel somehow enabled solar's capability (such as in your example) I'd agree. I doubt the "towing package" for a vehicle could meet the end specs without the larger radiator.

Without getting into the exceptions*, for the majority of owners it is best to understand that solar's purpose is to charge the battery. A solar setup does not require or add anything to a sub-panel configuration. A sub-panel is installed because of the inverter--just like the larger radiator is connected to the towing package.

Howard

*For those that want to know--in a Victron setup with the ESS Assistant in the Multiplus and the CCGX configured properly the system will use battery and solar power before using shore power even though the trailer is connected to shore power.The advantage to this configuration is the trailer only uses shore power if the battery SoC drops below a preset limit. The default is shore power has priority when available so the solar only charges the batteries.

If that explanation induces a headache in the reader, that's why it's easier to stick to "solar charges the batteries". That is how the vast majority of owners will utilize solar power.