Post #11, summary and THE END!
Final thoughts
Hopefully this somewhat long and verbose post of various experiments is of value and helps provide some insight and answers to some of the questions posed regarding use of a solar panel with an MPPT controller.
It certainly will help me get maximum power and maximum battery charge into my batteries when we go camping next summer. This last summer I was clearly doing some things that were NOT helping get maximum charge into the batteries.
First, I was ignoring cable power loss until my last trip and using long cables and parallel configuration. One of those “currents to low, it won’t be a problem”. On our last trip I did a series connection and thought I was seeing better performance, but while camping wasn’t going to spend time doing an experiment. Fishing was higher on the list.
Second, I really wasn’t paying a lot of attention to panel orientation. Mostly a “this looks about right”. Given that in the same time I could get optimal orientation, why not.
Since we don’t have enough solar, and DW likes to occasionally use the hair dryer, microwave etc. along with the furnace in the fall or fans in the summer, we seldom can use just solar to get the batteries charged. I typically recover between 50% and 80% of the power used the previous day. Keeps us from running the generator more than once/wk. But that also means the batteries can take ALL the current the panels can deliver. So minimizing losses is important for us,.
For those who can get to full charge before the end of the day, bits of additional power loss may not be nearly as big an issue but might let you get to full charge earlier in the day.
And I'd like to give thanks to those who were asking questions about solar and MPPT controllers. Trying to answer those questions was certainly valuable for my solar use cases, and a good brain excercise for a retired engineer.
