Hello!
Here’s my problem:
Victron SmartSolar MPPT 100/20
100 W panel, Voc ≈ 22 V
12 V 100 Ah LiFePO₄ battery
PV voltage drops to 12.6 V when connected
Normal operation after connecting another removable panel
I reconnect my panel and it works again for a day, then it drops back to 12.6 V instead of 22 V, so the battery doesn’t charge…
Thanks in advance for your feedback
Sounds a bit like a faulty module. As soon as current flows, the voltage drops too much.
The open-circuit voltage (Voc) is measured with no current flowing. Heat or other factors could be causing the module to sag so much.
Is it a new module?
Where did you measure the 12.6 V voltage? Directly at the MPPT charger’s PV inputs?
Hello
I get a voltage drop as soon as I connect the panel.
As there isn’t a 5V difference from the battery, it doesn’t start up.
I should mention that I installed update 1.74.
And I’m wondering whether it might have started since then.
Otherwise, the panel is 2 years old
I agree with @Jetlag . A panel may show good voltage and then fail once current starts to flow. Unplug it and test with just the portable panel. If it works it is likely your panel failing. This is assuming all your connections between the panel and the controller are good.
What you could try is draining the battery and then charging it with the module while measuring the voltage.
It should charge up to 12.6 V. If it doesn’t, or only charges very weakly, then the module is faulty.
Where did you measure the voltage?
Perhaps you could take some screenshots of the MPPT.
Voc stands for OPEN CIRCUIT voltage.
It is expected behavior to see voltage drop under the (charging) load.
Check Voltage of maximum power point in the specs - it might be just not the right panel for your setup.