back to 2022.09.05 LiFePO4 solar charging

4 sixteen panels in parallel series:




I had anticipated there might be problems with low solar production and had already set out the rest of my
panels, so I got to work rearranging them to boost production to the controller. I used four powerpole
distribution blocks to parallel four sets of four panels, and then plugged those into the new combiner.
This should quadruple the amount of current into the controller, which WILL be a problem if the sun comes
out, but I'm not expecting that to happen.

The sun was getting (invisibly) higher in the sky, and that in combination with the new panel arrangement,
started putting the new controller to work. I got almost 275w off the panels, leading to 265w (18.6a) into
the battery. That was getting close to the rated limit of the little controller, and it was geting warm to
the touch. Hotter still were the wires on the battery side, which are surprisingly thin gauge. (16 or 18ga?)
Unfortunately, the controller is sealed and potted so there's no way for me to upgrade the wire, but I suppose
that's the tradeoff for an outdoor controller like this is. Max charge current was 18 amps, pretty nice.

I was also a little entertained when I tried to measure the panel voltage with a handheld DVM. The panel
voltage was rapidly bouncing around, between 30 and 33 volts, which is something I had not seen on my inline
meters, probably due to them doing an average and slow update. This jumping around is probably caused by the
MPP tracking being done by the controller as it constantly jiggles the draw up and down a little bit to make
sure it's drawing the optimal amount of current from the panels at all times.

01 sixteen panels in parallel-series	02 progress 181W, 7Wh	03 progress 157W, 17Wh	04 progress 153W, 25Wh	05 progress 162W, 42Wh	06 progress 194W, 91Wh
07 checking parallel panels	08 checking parallel panels	09 progress 203W, 157Wh	10 progress 244W, 200Wh	11 progress 212W, 308Wh	12 progress 264W, 331Wh
13 progress 219W, 360Wh

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