This panel works on a cloudy day also
I didn't expect 100w in the Highlands in winter. But even on the cloudy days I was still getting 4w. Enough to maintain 13.2v in my 110amp caravan battery, and enough to stay off grid in the middle of a woods.
My panel is roof mounted so will never get direct Sun, but so long as it's light the MPPT charger is trickle charging the battery up to 13.5v and after 6 days off grid I was still starting the evening at 13.2v. This was enough to watch an hour or two if tv through an inverter, and enough that in the last day was able to drive the caravan 35ft out off grass and uphill on the motormover.
I did get proper plastic mounts for the roof and silkoflex adhesive and crimp connectors lastly I also added 2heavy duty 100Amp isolation switches to isolate the panel power and battery power.
The charge controller is awesome and works brilliantly with accurate information to monitor the state of the battery and charge info.
My battery would go to 12.5v after much use in the evening and charge back to 13.2v the next day even when there was no Sun, and this is October in the Cairngorns Scotland!
Great value kit, my experiments concluded the panel doesn't suffer from partial shading drop out issues and is a solid reliable performer.
I would thoroughly recommend it as great value.
Verified purchase: YesCondition: New