Hello Victron community,
I have bought Smartsolar 100/20 and 3pcs of "Sunpower series" Solarfam panels, each rated at 140w on my motorhome, mounted horizontally, and feeding 120AH AGM Battery.
I am however struggling to reach anywhere near the 420 Wp of the system. Yesterday at about 14pm CET at full sun and clear sky the output was 215w/(Batt Voltage 12.89 16.4A, under load attached to the battery of +-350w).
When I tried connect only one panel, the output was a bit over 70w, so it cleary has nothing to do with hitting the possible limit of 20A of the charger...
The panels are apparently some Chinese panels made from Sunpower cells sold under Solarfam (solarfam.nl) brand. I have a suspicion on "potential induced degradation" - have read that Sunpower cells earlier required positive grounding, and with the negative grounding they tend to loose 30+% pretty quickly, when potential builds on their surface. Have emailed the manufacturer about the grounding, but they have not responded yet.
My question is, would that be anyhow possible to try to test this positive grounding with SmartSolar 100/20, to see, whether it could be the cause of the power degradation?
I might isolate the frame of the panel from the vehicle frame, but I cannot find any documentation on how to go about this positive grounding.
Thanks very much for any ideas.
