Solar Charger, 21W Portable Solar Panel Kit Foldable IPX4 Waterproof for Camping, Solar Charger Power Bank Battery with 2 USB Ports for iPhone 11/XS Max/XR/X/8/7, iPad, Samsung Galaxy LG

Used one week at camp. Even on partly cloudy days it provides some charge.

When charging in high temperatures, cover your device (phone, tablet, power bank, drone battery, whatever) in insulating material like a heavy-duty mailing envelope (cardboard works better than cloth). I've had my devices stop charging at midday with three different solar panel brands - and guess where I live? Florida. At first I suspected the solar panels going bad, and since they're inexpensive enough, I'd buy a different brand. Eventually, though, a notice popped up on my phone - "Charging will continue when the device cools down."Insulate your device when charging in high temperatures.Another problem is what I call "backcharge." It's the gradual draining of your device's battery while connected to the solar charger when there's no sunlight. So keep an eye on whether the panels are still in the sunlight or not - which isn't as easy as you might think due to distractions by other things.

This thing is so sweet looking so excited to throw this on my hunting pack while it charges my phone love that it came with a cord hunting season can't come soon enough

I spent a week trying to test this thing and there are multiple things wrong with it.1. Its highest possible output on the bluest of skies with the sun straight up, was 10.9 watts.-- This is probably because they divide the wattage between the ports instead of sending all the available power to the only device thats plugged in.2. When you plug this directly into a mobile phone, it doesn't know how to negotiate with the phone to tell it to accept variable power of up to 10.9 watts. Instead it sends 3 watts.3. Sometime during the tests, it suddenly stopped working, it would no longer output any amperage. The green light was on, but it just wouldn't output any energy. The highest wattage I got during this particular round of tests was 5, and I was trying to figure out why because it was under the same conditions as the first day I tested with 10 watts coming out.--I'm unsure, but it may have also been a problem with one or two of the solar panels not working right. I put my hand over all three while watching a graph of power flow, and only one of the two panels shown any change in powerflow when I covered it up, the other two did not. I suspect that there's something wrong with the other two, or perhaps somehow it just wasn't using those two while not outputting the amount it was supposed to, I dunno. If I could deconstruct it I'd do so.I also believe that the covering they put on the panel's surface, reduces some of the potential light it can capture by a small percentage, but I'm not sure. It looks like it diffuses the light to prevent reflection, so perhaps it has no effect on its total collected energy? But thats just a personal thought. When I got it though, some of that had come off allowing shiny solar panel to be visible which makes me wonder just how much that covering hinders light.In the end, this needs to be able to negotiate with devices that can (phones) to tell them to accept a variable flow of amperage or something, so that the device can't lock the device to a max of 1.5 or 3 watts. If you're going to advertise this as portable power for your phone, it needs to work with the phone. Also, don't advertise something as having 21 watts if its only going to output half of that to your device. Its not 21 watts, if you split it between two devices. I suppose I'll have to be more careful of this "scam" in the future as all the solar panel manufacturers do it.

52 hour power pack 1 day new after year still good

I bought this for a 5-day backpacking trip. When in full sun it charged 2 devices just fine. In partial sun, it's only practical for one. But it easily attached to the outside of my backpack to charge while we were hiking. Seems good quality & I appreciate the included cord. It isn't as light as I would like it to be but it was dependable.

I haven't used it yet, since there has not been a power outage. It appears to be just the tool for the job.

Mine has 2 small nicks 2 of the panels, still seems to work ok, but unfortunate was