Measuring solar yield approaching winter solstice

I am not surprised by your numbers. My 9-watt, 0.6 amp, 15v, amphorous panel can easily maintain my pair of 6v T105's here in Minnesota. I have them directly connected to the battery-bank. No controller needed so no losses through a controller. I have a separate panel on the chassis-battery. The panels have been used for three years. Now on new batteries after 10 years use.