MPPT Con ?

[cal40john]

Originally Posted by hellosailor

Dave-
"But MPPT only applies to the technique of tracking the power point of the solar panel, it has nothing to do with the charging part of the design, that could be "
I'd say you're only batting 500 there.<G>

MPPT does not track the "power point" of the solar panel. It monitors the output voltage of the solar panel, compares it to the present voltage of the battery, considers the capacity of the battery (normally inputted during setup) and then uses a microprocessor to determine the optimum charging voltage and current. As part of that optimization process, there is some program or array that the microprocessor uses to determine what is "right" and by putting different numbers into that logic array (or formula, whatever they are using) you can just as easily use one-step, three-step, or continuous-step charging algorithms.

Whether the circuit uses lookup tables, or does real-time calculation, or any other means to make the determination, it is still analyzing the battery parameters and then making "decisions" as they change, and the panel output changes. Way more complex than "tracking" the panel by itself, whatever that would mean.

Maybe I'm reading this wrong but what I get out of this is that you're saying the MPPT controller is always trying to find the max output of the solar panel, then if it determines that the battery should be in a float stage it now does what with that excess energy?

That doesn't make sense. Whatever algorithm is used to charge the battery, only when the controller is in the mode of dumping as much energy into the batteries as possible does finding the max power transfer point make sense. As soon as the controller starts reducing current to the batteries it is throwing away energy from the solar panels. It is opening or shunting the panels, this is deliberately moving away from the max power transfer point.

John