Voltage spike every hours

[Win9889]

Hi everyone,

I am quite new to this solar panel thingy and am trying to understand it. I measured the voltage, current and power from my Tracer- BN Series (Models:Tracer1215BN/Tracer2215BN Tracer3215BN/Tracer4215BN) which is connected to the Offgridtec 100 W 36V mono solar panel (3-01-010510). The graph attached is the data I got via Modbus RTU RS-484(2 wired). I want to understand why is the voltage remains constant throughout the day and there are also voltage spikes regularly every hours. I think the spike is becuase MPPT searching mode or something but dont quite understand it. I would be very happy if anyone could provide me with the answer or even a link. Thank you.

graph solar.png

[inetdog]

I think you are indeed seeing an MPPT scan by the Charge Controller. The voltage stays the same most of the day because the panel Vmp is almost independent of the amount of sun hitting the panel. Imp varies directly with insolation, as seen in the Current graph. The dip to near zero is also probably a full range MPPT scan. The upward blips in the power graph are probably a measurement error.