Today I ran the solar powered pump the entire day for the first time. I am very pleased with the results.

Ever since I solved the voltage spike issues we’ve been having with all of our power electronics circuits over the years, I’ve been very excited to actually try out the new pump controller circuit on the real pump in the real pond. It has been quite busy, so I didn’t have a chance until today. We installed the prototype circuit last night and turned it on at 7.30AM this morning, and it was still going strong when I last checked it at around 7PM.

Here is a photo of the circuit in the power box:

You can see that the battery voltage is at 26.1V. The prototype pump controller circuit is the board with all the wires coming out on the lower right side. We can clean it up once we’ve confirmed it is working well over the next few days.

Here I’ve switched the charge controller to show how much current is flowing from the solar panels to the batteries:

It is showing 12.5A which is less than I would have expected from 2x 300W solar panels on a very sunny day around noon time. (At 26.1V, 600W would give about 23A minus whatever losses were in the charge controller.) My best theory, though, is that 26.1V means that the battery is basically still fully charged so the solar panels are mostly just powering the pumps.

Here is one last picture of the charge controller showing the current to the pumps:

I ran the pumps at around this level (10A-12A) for most of the day and then dropped it down to about half that to run it overnight. If all goes well, the batteries might be about half discharged in the morning and I’ll be better able to see how much power the solar panels can actually produce tomorrow. That is, if I can observe it with a sunny sky around noon time again.

It is worth noting that the day turned overcast later, so around 4PM with the sun lower in the sky and hidden behind clouds, it dropped to about 4A, which is only about 17% of the rated power of the panels. This isn’t too surprising, though. But I thought it was a good number to know.