It works! Manual MPPT controller v2.0
Well this $10 shipped DC-DC buck converter lets me find the maximum power point from one solar panel as it charges a battery. The panel output in morning light varied from 39 watts at the panel vo...
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Ok got it set up a little better. I have a 250w draw at the battery to keep the battery voltage steady as I vary the output pot. I put my watts up meter at the input to the battery so i could see real watts in and a turnigy at the input to the buck converter.
With the current sun I am getting 46.2 w in panel direct with a battery voltage of 11.77v. Maximizing power from the panel by finding the max power point at this moment of 14.9v I am getting 52.5w at the battery after DC-DC conversion losses. Not a big power difference but more than 10% real world gain right at the battery, and at a medium state of charge rather than fully discharged.
95 degrees out in the sun with a very thin haze/whitish blue sky (fair amount of moisture in the air but no clouds as such).
A little more playing and I got a peak of 4.57a at the battery from nominal 4.1 NOCT (800 w/m2 - most I have noticed is just under 4.1a that I can recall) Isc 12v panel. I think I'm sold. 5.1 is theoretical Isc at 1000 w/m2 but I have not seen close to that.
Jim
With the current sun I am getting 46.2 w in panel direct with a battery voltage of 11.77v. Maximizing power from the panel by finding the max power point at this moment of 14.9v I am getting 52.5w at the battery after DC-DC conversion losses. Not a big power difference but more than 10% real world gain right at the battery, and at a medium state of charge rather than fully discharged.
95 degrees out in the sun with a very thin haze/whitish blue sky (fair amount of moisture in the air but no clouds as such).
A little more playing and I got a peak of 4.57a at the battery from nominal 4.1 NOCT (800 w/m2 - most I have noticed is just under 4.1a that I can recall) Isc 12v panel. I think I'm sold. 5.1 is theoretical Isc at 1000 w/m2 but I have not seen close to that.
Jim
