Hi,
I have a DIY system which works fine since 2023, however I have always had this problem:
Regularly, my MPPT 250/60 rev2 (firmware v1.64) will go into what seems like a “micro-search” mode, spiking the voltage around by ~20V permanently and thus reducing yield by around 5-10%. I think it’s best explained by these graphs:
You can clearly see the regular scans every 10 minutes, this is normal. But notice how at around 10:10 the power suddenly starts to spike around, then at 10:31 the blue line becomes smooth again, at 11:20 the yellow line and at 11:37 both are smooth again.
This is without rhyme or reason, it just seems to randomly come and go. There’s basically no shading there, it also happens on totally sunny days when both rows are fully exposed and no shading whatsoever. Usually when I disable and re-enable the charger in the MPPTs via the Victron app, it will stop doing that, until it starts again randomly.
Setup details: Multiplus II GX 48/5000/70-50, 2x SmartSolar MPPT 250/60-Tr rev2 (each with 6 JA Solar 405W panels), JK BMS via Bluetooth (serialbattery) LiFePo4 battery.
I used to have a SmartSolar MPPT RS 450/100 with the exact same setup before, and it never did that.
Thanks for any pointers.