MPPT Firmware 3.16 Issues

DIY
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@guystewart , this is just an update on using the new v3.16 firmware from this post on the old Community (https://community.victronenergy.com/questions/311244/mppt-firmware-315-and-mandatory-updates.html#). I was going to reply directly to that post, but I could not seem to upload images on that site.

The updated firmware did not correct the problem I had with the two systems described in the previous post. I installed the new firmware on July 24th and my system hit absorption on that date. However, it did not hit absorption again for about another 10 days on August 2nd. Then it did not hit absorption again until August 11, when I reverted back to v3.13.

Now, some of the days I did not have the daylight to reach absorption charge, which is understandable. However, there were several days where my SOC peaked to ~99% and held without hitting absorption (e.g. July 29 - Aug 2).

Shown below are some graphs from the VRM for reference.

Screenshot 2024-08-19 225311
Screenshot 2024-08-19 2253111153×1718 214 KB

Let me know if you need any additional information for help with this. The image and description above is from my 12v system, but also my friend’s 48v system had the same issue. His system his absorption for one day, then did not hit absorption again until he reverted back to v3.14.

Thanks again for your help!

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Do you have any shading issues that might cause the MPPT algorithm to miscalculate the operating point? i.e.partial shading on a string?

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Hey Mike,

I haven’t dug into the MPPT algorithm, so I’m not well versed in exactly how the algorithm is designed.

But regarding the partial shading, there’s two installations where I’m having this trouble. One is mounted on an RV roof, and the other is mounted on a standalone structure. Both systems use 3 MPPT controllers. The RV one could see partial shading at times, but the ground mounted one is out in the open and sees full sunlight for the majority of the day.

Both of these systems see issues when on the 3.14/3.15 and now the 3.16 firmware. Reverting back to the 3.13 firmware corrects this issue, which points me toward it being an issue with the firmware.

On a side note, I thought providing an update on the performance of 3.16 from my prior post might have sparked some interest/concern/questions from Victron staff, but nothing yet.