I decided to do output readings on these small solar chargers. One is for camping and one is intended for maintaing ATV power sport batteries. I was surprised at the output and the final results. It was a super cloudy day and a good excuse to make a video experiment for my YouTube channel.
I didn't really prove much but I learned a few things about solar chargers and how they work in dark cloudy winter conditions.
My interest in rapidly growing in solar and wind and renewable energy, even though I joined permies for the rocket stoves forums, I thought why not share my experiment with you guys...?
You are reading what is called open circuit voltage. Removed from load it does not tell you anything. Traditionally those thin film panels have an open voltage reading of 26 volts or more in full sun. See if your multi meter has a amp meter reader. Better ones do usually up to 10 amps. That would give you a better idea. You want to measure power which is voltage×amperage not just voltage.
Best regards, David Baillie
Yes mine reads up to 10 amps, and I did read the amperage, and I put the Coleman folding charger under a load by charging my iPhone with it. The Coleman read 0.33 amps and the other one only read around 0.04 I think. I did include the amperage readings in the videos.