Quote:
Originally Posted by rickst29
.............snip................
With Panels in Parallel (for PWM) the lowest voltage among the multiple panels "on the string" will determine the Operating Voltage of the "Parallel String", while the Current of all the panels is combined at that Voltage.
But with Panels in Series, (for MPPT), you want to keep the Imp Current values close: The Voltages simply add together, and widely differing voltage values do not cost power on the "Series String" as whole. But the lowest Current among the panels on the "Series String" determines the performance of the String as a whole, limiting the higher-current panels to the current value of the lowest panel. (That is why a shaded panel degrades a Series String so badly).  |
This is a very important point to keep in mind so I am going to
steal it from rickst29
When I suggested the 120 to 150 watt panels for the front shell, these will have an Imp of 7 to 8 or 9 amps where as the 100 watt panels Imp will be around 5 to 5.5 amps. So what rickst29 is saying is you don't want to series a 100 watt panel with a 120 to 150 watt panel.
In this case you would want two series banks to feed the MPPT CC one made up of the 120 watt to 150 watt panels and the other bank the 100 watt panels.
Rule of thumb for series panels, Vmp to battery bank voltage ratio is 2 to 1 and don't go higher then 4 to 1.
@rickst29 keep up the "nitpicks"
