I've noticed that some days the MPPT doesn't really kick into high gear. Today it was sitting at 1.6kW at about 11:30 whilst I was expecting much more since it's clear open skies. And yes, there's batteries to be charged so the requirement for power was definitely there. I turned off the solar switch on the inverters and when I turned it on again the solar production immediately jumped to 4.7kW and it's doing 5kW now. Would this be a bug in the firmware or why did the MPPT "idle" at much lower production values until it was booted?

Edited October 2, 20232 yr by p_i

What was your PV voltage during this low production time? I've had it happen twice in the three months of owning my Sunsynk 5kw where the MPPT gets stuck on a low voltage and is only fixed by a PV disconnect or inverter restart. I believe it's a firmware glitch but haven't gotten around to loading the latest firmware. I'm on COMM:E426 - MCU:3382-1515.

Here are two successive days PV voltage - both relatively sunny conditions with the first having the MPPT glitch. You can clearly see the MPPT locked at 208V instead of varying around 300V.

My voltage was pretty much in the normal range for me, which is 330-370V. It's only the current and power which wasn't anywhere close to the previous day. And yes, the bump up at 10:19'ish is due to partial shading which is resolved around that time.

@JaseZA I appear to have a similar scenario: the MPPT appears to get stuck at a lower voltage. I have been experimenting with this today, in fact: I can get away from the false maximum by switching on my kettle and temporarily forcing a higher grid draw, but... the cycle repeats itself.  I have been contemplating an inverter shutdown and restart until I saw your post now.  I have set up a temporary Home Assistant notification to my phone to detect a lower than normal PV voltage so I can go make a coffee 🙂

See below the graphs for the steps in PV voltage, and correction after I switch the kettle on. One can also see the unnecessary dips in PV output power.  I would be interested to hear if anyone has experienced the same and has come up with an explanation and solution.

 

 

Edited October 2, 20232 yr by shovelhead

PS I'm on COMM:e419 - MCU:3162