I’ve been using Victron ESS for quite a long time now (since around version 3.60), and I need to be honest — this issue with MPPT throttling has been present for a long time and still isn’t properly resolved. My setup is not unusual: AC-coupled inverter (Fronius) + Victron MPPT + battery. The prob…

Hi, I would like to share a final update regarding the issue. After a detailed inspection, I decided to redo the entire DC side to eliminate any potential weak points. The following changes were made: all MC4 connectors were replaced with original Stäubli EVO2 and properly crimped MC4 Y connect…

[image] Oldrich: While the behaviour seems improved compared to before I would be very surprised if it was fixed. Nothing changed. The drop in production is not commanded by the GX device, it appears to be the MPPT itself reacting to something. A rescan usually happens only if there is a sud…

Thank you for your explanation. In my case, the behaviour seems much more extreme than a normal rescan. As you can see in the attached video, the MPPT power drops very close to 0W even though solar conditions are stable. This does not look like a typical short rescan that lasts only a few seconds. …

Hi @Oldrich77 , I added some additional monitoring on my side to see if we can catch enough data to diagnose this. Now we wait for data.

Thank you, I appreciate it. I will continue monitoring the system and provide timestamps and additional data if I observe another drop.

I think we already have something to work with. You are right. You can see the rescan squigles on this chart, plus that one time where it completely drops out. [image] The Multi is lowering the charge voltage. Let me look into this some more. This is not the first time I’ve seen something like th…

Thank you for your analysis, I really appreciate you looking into this and working on it. I will keep the system running as is and continue monitoring. I fully trust that your team will get this resolved, and I am glad I could help identify a problem that is not easy to detect.

Just to let you know, I have updated the system to the latest beta version (3.80.14). I will continue monitoring and will report any changes in behaviour.

This might be simpler than we thought. Your site did this again today around 10:33AM. Data logging says the reason for the outage is no input power. Check your PV wiring, it might be as simple as a loose connection.

Thank you for the suggestion. I will check all PV wiring and connections to make sure everything is secure. However, the behaviour seems very fast and the power returns immediately, which made me think it might not be a physical connection issue. I will verify and report back.

Just a quick update – I checked and retightened all PV connections at the MPPT, as well as all DC and AC protections. I will keep monitoring.

ESS throttling MPPT without valid reason (AC + DC system, battery not full, reproducible

DIY

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ESS throttling MPPT without valid reason (AC + DC system, battery not full, reproducible

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