Solar Controller (cheap china)

Almot wrote:

Well, since we deviated into panels discussion...
Vmp/Imp exceeding the specs is not necessarily good. This Sharp in Solar Blvd guarantees +10/-5% accuracy of Vmp/Imp (and so does the unknown Perlight). -5% is a bit low if you happen to have it. +10% is too much deviation when you connect 2 panels, MPPT controller gets confused. I prefer having no more than +/- 3%. Not all the Sharps are that "bad", some models have +5/-0% tolerance. Frames of Sharp come in 4 different profiles see Figure 1 and corresponding model number, important thing when you use side brackets.

Never considered the tolerances and although great info, I'm not too concerned over that. I'm interested in getting a certain amount of Ah per day and anything over that is gravy. Having a larger battery bank does that for me. :) About Sharp panels, it meeting or exceeding its spec is great to me because that means it will at least put out its rated power or very close to it. Even though Perlight is cheap, I have no idea of its performance. I have a Trina panel bookmarked because of its wattage rating but no idea on performance.