Solar Panel output in the shade?

[hotfishtacos]

I've got 2 panels mounted on my Escape 19 and almost always camp in the sun if we are boon-docking. The trailer is pretty well insulated and I roll the awning out if I want shade. Since most other campers want shade I can almost always get a sunny spot to camp. Even a little shade takes away a lot of solar charging power. For example, about 2" x 12" of shade on the edge of one of my panels from the Maxi-Fan will cut the panel output by 75%. I've since taken care of that by raising my panels. My 95 watt panels put out around 6 amps each in full sun and an overcast day I will sometimes see 1.5 amps or less. If you have solar you want sun. If you have portable panels you can park your trailer in the shade and move your panels into full sunlight...the best option for some. Most solar chargers have a display panel showing charging amps and battery voltage so you don't need any of those aftermarket meters. I bought one and never use it.

[Steve L.]

Here's one guy's experiment with repect to how long you have to "rest" a battery before you get an accurate idea of the battery's state of charge. Note also Trojan's opinion of open circuit voltage measuring.

Reader's Digest version: after a little over two minutes on the charger, the battery voltage still wasn't correct after more than 11 hours of battery rest.

Just my (well his) 2 cents worth...

Measuring A Lead Acid Battery State of Charge Photo Gallery by Compass Marine at pbase.com

[Ron in BC]

I've always been aware of the surface charge after charging and I've always used a load like turning on a light etc. to remove it before judgeing the battery state.

Maybe removing the surface charge in an inexact way isn't lab level accurate but at the end of the day my brain converts the battery condition level into a basic poor, fair, good or excellent