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martijn15 asked

MPPT doesn't keep high output after power sweep

I have an SmartSolar 150/35 MPPT charger connected to 3x 24 370 panels. The charger is connected to a single 25.6V LiFePO4 battery, Which is connected to an victron Phoenix VE.Direct 24/1200 Inverter. I am making screen recordings of the victron connect from both the mppt & inverter. The first week the system performed well.

Now the system is outputting very low power (<120W) in bulk charging but going up to the normal 300-600W every 10 minutes for a bit before going down to <120W again for the next 10 minutes. I assume the algorithm is doing a sweep every 10 minutes. The image shows the PV voltage & yield over 2 hours. It can be clearly seen that the power is good during the sweep but drops of in between.

My question is why it doesn't keep any of the high output it clearly finds during the sweep? Could it be anything with the Load output settings? I made changes in an attempt to protect the battery bms from over discharge and put the restart voltage too high (>28V). I found out a few days later when it first reached the indicated low voltage point (20.5V). I changed it, but only to keep the above mentioned behaviour, I have tried resetting the factory settings and to set it to always on, but it doesn't want go back to normal charging.

mppt-behaviour.png2 hour history

MPPT ControllersMPPT SmartSolarmppt charging
mppt-behaviour.png (35.9 KiB)
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1 Answer
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martijn15 answered ·

After accidentally changing the battery type to gel batteries and back the MPPT is performing as normal again. I would still be interested in knowing what happened to be able to avoid it in the future.

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