Cheap China Solar Controller Failure
For a couple days been noticing higher than the 14.6 voltage,.....going to 15, and even 15.5,....I knew something was not right. The next day it was showing 16, then quickly went to 17+.......I quickl...
Forum Discussion
You need even numbers of matching panels
EXAMPLE
The panel I mentioned in a previous post 17.2 volts 4.6 amps 22Voc
A pair in series would be 34.4 volts at 4.6 amps 156 watts
You then parallel that with another matching series pair of the same thing
You get 34.4 volts at 9.2 amps for 312 watts
Connect this too the input of an MPPT controller
The advantages are you have parallel strings do if one pair gets some shade on one panel , only the output of of one pair is reduced
When you have a series string shading one panel reduces total output
With parallel string, you have more amps, at lower voltage and more voltage drop per foot at the same watts, put less effect from shading
Series parallel, gives you some advantage of each, but requires MPPT just like a straight high voltage series only system
EXAMPLE
The panel I mentioned in a previous post 17.2 volts 4.6 amps 22Voc
A pair in series would be 34.4 volts at 4.6 amps 156 watts
You then parallel that with another matching series pair of the same thing
You get 34.4 volts at 9.2 amps for 312 watts
Connect this too the input of an MPPT controller
The advantages are you have parallel strings do if one pair gets some shade on one panel , only the output of of one pair is reduced
When you have a series string shading one panel reduces total output
With parallel string, you have more amps, at lower voltage and more voltage drop per foot at the same watts, put less effect from shading
Series parallel, gives you some advantage of each, but requires MPPT just like a straight high voltage series only system
