How many panels can I hook to my charge controller

TheFudd

Hi there, new to the forum and to solar as well. A little background, we live full time in our RV and looking to get it setup for off grid use.

Currently we have 4 - 100 watt Renogy 12 Volt panels(flat mounted on the roof), Renogy Rover MPPT 40A Li charge controller, 4 - 100AH AGM Renogy batteries (yep it was all a kit), and a Go Power IC3000 inverter/charger. 

Being so new to this I've been watching the voltage readout on the display of the remote panel for the inverter to determine the battery level. Seeing the voltage drop so quickly while using even a small appliance worried me so reading a bunch online I see that is not the correct way of check battery level so I have a monitor arriving Monday to help with that.

Not knowing yet how much power we actually draw/use with the various appliances in the rig I don't know how much we will need to replace with the solar panels.

We are currently in the western Arizona area and watching the charge controller app we typically are getting 140 - 160 watts out of the 4 panels during the afternoon sun. 

This leads to my question: the charge controller specs say max input of 520watts @ 12 volts, is this determined by the rating of the solar panels or how much wattage is actually coming out of the panels? 

Rating of the panels: I can add one more before needing another charge controller for any additional panels.

Actual wattage: with the way my current panels produce I could add up to eight.

My guess is go by the rating of the panels but want to hear from others who are more knowledgeable. Thanks for reading. 

Photowhit

TheFudd said:

We are currently in the western Arizona area and watching the charge controller app we typically are getting 140 - 160 watts out of the 4 panels during the afternoon sun. 

Sounds like your panels are mounted flat on your RV. The output should improve when the sun is higher in the sky going into summer, perhaps up to around 300 watts.

If your manual says 520 watt max, then yep, 1 more panel. Some MPPT type charge controllers can handle over paneling.

TheFudd

Thanks for the reply Photowit, I didn't think about the height of the sun changing and getting better performance during the summer.