As Subaru297 said x2. I went back and looked at a lot of the reviews for the SOLAR 30/30 and there are a lot of inconsistencies, yes even voltage issues. I would say that the voltage discrepancy is more than likely a software/firmware issue in the voltage/amp calculations.
If the controller is no longer under warranty, you could open it up and look for a POT (not that kind), it is a variable resistor that can be adjusted. Most voltage display units, especially the inexpensive ones have them designed into the circuit board. This is so that the Q/A (if they have one) can fine tune the voltage with a known voltage source, prior to shipping the unit.
Personally, I would invest in a good SOLAR charge controller, be it PWM or MPPT (of course I am partial to the MPPT controllers as PWM only uses 75% of the panels available wattage) and you will probably eliminate the voltage discrepancies. There is limited roof real-estate so I would go for more controller than adding panels to make up for the PWM losses.
How did you do the 22 panels at home. Did you go with Micro-inverters on each panel?
Have a GREAT EVENING!!!!
2013 Jayco Eagle 284BHS
250Watt Grape Solar Panel, MorningStar MPPT 60 Charge Controller
1500 Watt Ramsond PSI, 2 Trojan T145 Batteries (260Ah)
2 - AirSight Wireless IP Cameras (used as rear view cameras)
EnGenius WI-FI extender, D-Link wireless (n) modem
MagicJack Internet Phone
2012 Ford F150XLT, EcoBoost w/3.73
157" Wheel base, HD Towing Package
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