Panels charge half of the usual

[fiox89]

Something doesn't add up. Panels are in series, VOC should be 36V, and 25.6V at MPP seems OK.

But short-circuit current was 1.2A and suddenly you have 3A in the Victron app.

But ignoring the above - if your panels produce 40W during noon with a clear sky and are perpendicular to the sun - go for new 100W panels. I would expect ~70-80W in that scenario.

I agree, these values are not clear, yet I have these measurements... repeated several times... I will look for a solution to mount traditional panels..

 

[sunshine_eggo]

I just remembered a detail. The day the panels stopped delivering as usual was the day I took the vehicle to the mechanic. That day, in a hurry, I first disconnected the battery from the Victron mppt, and then disconnected the panels from the Victron. The vehicle was in the sun.

Is there any possibility that something happened in this operation?

Highly unlikely.

You've also verified:

1) abnormally low Voc
2) abnormally low Isc

You should always shut off the controller, then disconnect solar, then disconnect battery. In that order.

This is not true of Victron controllers. They do recommend you turn them off first before disconnecting PV, but it is not required to remove PV first and battery second.

They explicitly state operation with only panels is permitted AFTER the MPPT has been connected to a battery to establish system voltage. After that, they can literally operate batteryless.