Thanks again everyone for the help. Sounds like an adjustable controller might be a good idea. If I do go with option B(adding a third 120 watt panel to my current 240 watt system and using the Blue Sky 30 amp mppt controller) I have another question. Currently my two 120 watt panels are wired in parallel with 10 guage wire down a vent to the existing controller. Should I have the additional 120 watt panel run with a separate 10 guage wire down the vent and then spliced together with the current wire at the controller, and then 6 or 8 guage wire from controller to batteries?