I have reviewed manuals for several SmartSolar MPPT charge controllers. Section 3.3 "PV Configuration" lays out the guidelines for the solar array. It gives minimum, recommended and maximum number of individual solar cells in series, i.e. " Minimum number of cells in series: 72 (2x 12V panel in series or one 24V panel)".

** Is the number of cells important or is this a generalization to get the user in the correct operating voltage range?** That voltage range being Vbat+5 to 10-15% below the voltage limit.

For example, charging a 12v battery bank with a controller that has a recommended series cell count of 72. Using a single 24v panel, would it matter if the panel had 72 cells or 60 cells as long as the voltage is within the parameters?

I am using the Victron Energy MPPT Calculator Excel spreadsheet to determine voltage range vs temperature for individual panels.

Thanks