It was even able to charge my iPhone on an bright overcast day from 30% to full in an hour and fifteen minutes

I tested the panels on a cloudy day in Northern AZ (that’s right

It was charging extra slowly on a cloudy day, but in bright sun during the summer it's wonderful

We left it out on a cloudy day to charge an Ipad and a cell phone.

I've been leaving it in the car during the business day to charge my phones (personal and business) and every day by lunch and after work, they're both charged to 100%... even on partly cloudy days.

I was able to charge my anker bluetooth speaker even inside a building in a cloudy day with no sunshine whatsoever

Cloudy days and shadows moving into the solar panel areas isn't a big deal

Even on a partly cloudy day it does almost no charging

Even on cloudy days it put charge in my iPhone 8plus and GoPro Hero

Charged everything up on a partly cloudy day in a couple of hours

I tried it out on a partly cloudy day and it worked well

i tested this panel with a drok tester on a clear day with the sun at it's highest

Good output, even made a small current on a very cloudy day

On a clear day, I can get 15% - 20% of my iPhone 6s battery's life back in 45 minutes!

I bought this solar panel because I am into backpacking as well as long day hikes

With a cloudy day, your performance will be abysmal

I bought this for a northwoods canoe trip where I wouldn't have anywhere to charge my phone, and the first day in the canoe it was partly cloudy.

Somewhat flimsy D-ring carabiners

I took it with me on a trip to Yosemite National Park and it performed great, I was able to charge my portable bluetooth speaker and my cellphone while we were having a quick bite by the trail, I can't complain about this unit, please note that the charging will work as long as you have a nice open view of the sky, if its' cloudy it will charge but not as quick as when there are not clouds

It will even overheat in the panels pocket as it is all black

Recently purchased this item to have as an additional 'power source' for a bug out box, as well as to have for traveling purposes