ANOTHER D*** Solar Question!!!!
Just upgraded trailer to a new, much larger trailer (Timber Ridge 280RKS) which has a "huge" 10W Zamp solar panel. The panel is wired directly to the battery through a master switch and 30A breaker. ...
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They all do the IV curve. MPPT in MPPT mode tries to keep in one place on that curve. "Imp" is just a value of I on the I curve which I is the same as the Isc you would get at the time. It is convenient to just say Isc instead of I but it drives some people crazy knowing you can't really measure Isc except with a disconnected panel. But you can get Isc just by getting I, since they have the same value.
Some solar controllers simulate tapering by changing the "duration" of the on and off cycles after the batteries reach the controller's high set point voltage (absorption voltage in some cases but not with the straight on-off shunt controller types that have a lower set point too) Confusing? Nah.
Even though as the battery rises in SOC and they have the off times get longer and the on times get shorter, this does not mean the amps during the on times stay the same (*but it might--see below). They get less, same as a straight tapering controller's amps then.
I used to watch that action on my Trimetric with my first controller which was an ASC "low frequency PWM" type, which is what they call that action.
*However there is also the problem of the insolation getting less later in the day, which muddies the picture by causing fewer amps
The solar amps being so low compared with the AH capacity of the battery bank, you don't get to Vabs until well into the 90s SOC percentage, so it isn't much from there to when you would drop to Float with some controllers anyway.
Some solar controllers simulate tapering by changing the "duration" of the on and off cycles after the batteries reach the controller's high set point voltage (absorption voltage in some cases but not with the straight on-off shunt controller types that have a lower set point too) Confusing? Nah.
Even though as the battery rises in SOC and they have the off times get longer and the on times get shorter, this does not mean the amps during the on times stay the same (*but it might--see below). They get less, same as a straight tapering controller's amps then.
I used to watch that action on my Trimetric with my first controller which was an ASC "low frequency PWM" type, which is what they call that action.
*However there is also the problem of the insolation getting less later in the day, which muddies the picture by causing fewer amps
The solar amps being so low compared with the AH capacity of the battery bank, you don't get to Vabs until well into the 90s SOC percentage, so it isn't much from there to when you would drop to Float with some controllers anyway.
