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 sunA few minutes later with load ofaround 300w - full sun.
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