The "4min" pictures show the effect. In this case we came from Float. The battery is full, no current is flowing. Everything is fine. Then at the load output of the MPPT a light bulb is switched on - about 2 A the bulb wants to pull at 12.75 V = 25.5 W. Makes sense. But the load from the generator starts to swing now from zero to 150 W.4min Solar (W) and Load (A) 20190730-093526.jpeg
The charge controller seemingly can't cope with controlling that, because when it tries to take the voltage back up, it brakes the water wheel, voltage drops and current goes down simultaneously.4min Solar (V) and Batt (V) 20190730-093613.jpeg 4min Solar (A) and Batt (A) 20190730-093635.jpeg
The pictures "42min" show the course over a longer period. Sometimes it goes smoothly for a few minutes, but then everything oscillates again. 42min Solar (W) and Load (A) 20190730-112209.jpeg42min Solar (V) and Batt (V) 20190730-112228.jpeg42min Solar (A) and Batt (A) 20190730-112249.jpeg
The currents jump up to 10A and down to 0A. You can also hear it in the running noise of the system, how the generator grabs and brakes and then lets go again. Definitely not good electrically for the battery and mechanically?
Is there a trick for hydropower units? From my point of view, the charge controller is too fast? If it were a PID controller, you could tune it. But I didn't find any parameters that could be tuned.
We are at a water wheel with a weight of approximately 1 ton (3.5 m diameter, 1.5 m wide); with the water flow and fall height, theoretical power 100 W, rotating at ~ 10 rpm IMG_3530.jpg-> 3 stage gear system to increase rpm IMG_20180323_181324.jpg-> 3-phase AC generator (ZXA 50500) -> bridge rectifier -> BlueSolar MPPT 75/10 -> 100 Ah 12 V battery