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
KJINTF wrote:"The expected amps with MPPT does change with battery voltage where you get more amps out of the same controller output watts when the battery voltage is less"
Please explain this statement - I'm confused
As others have said. This also relates to how you can get more amps running big loads. A big load will knock down the battery voltage.
When MPPT does get you more amps than PWM as when panel temp is low, say 44C, then you still don't get all the panel output. You just aren't "losing" as much of it as PWM does.
Take the case where my 230w MPPT is getting 14.5 amps with panel temps just so, where I would also be getting Isc with 230w PWM, namely 14.5 amps and let's say battery voltage is 13.2v
Controller output watts is 14.5 x 13.2 = 191w in both cases. Now with the PWM, if I drop battery voltage to 12 I will still get the same 14.5 amps but with MPPT I should now get 15.9 amps!
So your MPPT salesman will be sure to do his demo at 12v battery so it beats the heck out of PWM, and not wait till battery gets to 13.2v when they are equal :) He will also try to do his demo on a sunny day at 10,000 ft at 32F ambient.
