question

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matt09 asked

SmartSolar 100/20 reports battery voltage higher than actual volatge

I have a Smart Solar 100/20 installed for about 2 years and recently I have noticed that it shows the battery voltage to be about 1.3v higher than the actual voltage measured at the battery terminals on the MPPT.

There is also a 150/60 on the system which shows the correct battery V.

Both are firmware 1.63 - I tried the beta C1.64 out of interest and also 1.61 but the error is still there.

System:

  • MPPT 150/60 3300w panels
  • MPPT 100/20 810w Panesl
  • Multi 48/5000
  • 4x Pylontech US2000B
  • Cerbo (fw 3.30)
  • 100% off grid

Under load of around 2400w - battery 100% full sunimg-0297.jpegimg-0298.jpegA few minutes later with load ofaround 300w - full sun.

img-0299.jpegimg-0300.jpeg

Multi meter shows 52.4V at battery terminals of both MPPTs

I left the 100/20 disconnected from the battery and panels overnight and the error was at first a bit less - around 0.7-0.8V but gradually rose to the current 1.3/1.4V.


Edit: I suppose the question is - is the controller faulty and need replacing?? It seems that when charging and the battery voltage rises the 100/20 is throttled when it "reports" over 52.4V even though the actual voltage is nearer 51V....

Any thoughts?


Thanks

MPPT ControllersMPPT SmartSolar
img-0297.jpeg (110.0 KiB)
img-0298.jpeg (75.9 KiB)
img-0299.jpeg (110.0 KiB)
img-0300.jpeg (73.7 KiB)
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2 Answers
matt09 avatar image
matt09 answered ·

MPPT replaced under warranty - thanks Victron for an excellent service!

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matt09 avatar image
matt09 answered ·

Reported battery voltage remains higher than the actual battery voltage by around 1.4V

All connections between the MPPT and the battery have been remade and the fuse in the MPPT has been replaced - the problem is still there.

What should I do next?

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screenshot-from-2024-05-05-11-55-59.png

screenshot-from-2024-05-05-11-56-57.png

Missing out on potential charging....


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