Using USB ports on RV solar controller

[JDK2078]

If I plug into a USB port on the charge controller in my RV does it provide power directly from the solar panel on the roof or from the RV house batteries? Just trying to figure out if it makes any difference using USB outlets in the RV vs those on directly on the solar controller panel.

 

[sunshine_eggo]

If I plug into a USB port on the charge controller in my RV does it provide power directly from the solar panel on the roof or from the RV house batteries? Just trying to figure out if it makes any difference using USB outlets in the RV vs those on directly on the solar controller panel.

I can't say anything to your specific controller since you haven't provided that information, but they typically operate as follows:

Battery power powers the charge controller, and the power for the USB comes from the batteries.
Battery power powers the charge controller, and the power for the USB comes from solar if it's available.

I have seen an instance where a charge controller would power the USB purely from solar even when disconnected from batteries.

You can always test it yourself.

 

[JDK2078]

Thanks. This is the controller.

 

[efficientPV]

always from battery on that one which means it is always a current draw.

 

[JDK2078]

Thanks for the information

 

[sunshine]

This is the controller.

The displayed CC certainly charges faster during the day when compared to itself at night.
But they are all on the battery circuit.

 

[fratermus]

always from battery on that one which means it is always a current draw.

In my testing with similar models the USB shuts off with the LOAD output at LVD.