if that 16.5V really is Voc (so read at the panel with the controller disconnected), it is not good and likely points to an issue. If I give an example of how one controller works .... the
Victron MPPT
Solar Controller will not even wake up until the Panel voltage is >5V more than the
Battery - so if you had a
Victron controller with your panels, the Leisure
Battery would have to be under 11.5V before the
solar would do anything at all.
With the
battery full, you really can't tell what the panel is capable of - you need a demand of at least 8A (could be
battery charge or something else) with a 100W panel to see what the panel could output. A
s an example, from around 15:00 my 270W array are only putting 100W and dropping all the time - but that is because that is all the batteries are accepting and not a limit of the panels. This is evident at the jump in power at 15:10 and 16:45 - which is when the fridge gets powered up. And as soon as the compressor no longer takes power, the
solar harvesting drops back again. And even then at these jumps I don't know if the
solar is peaking or not.
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