ECEENPortable Solar Charger, 20W Solar Panel Charger for Cell Phone with Dual USB Output Waterproof Foldable Camping Solar Pnaels Survival Emergnecy Kit for Tablet GPS iPhone Camera & USB Devices

Durable for backpacking. In the sun, it charged phones about as quickly as they charge while plugged in at home. Maybe faster. Roughly 1% per two minutes maybe. The phones seemed to charge so quickly they thought they were 100% early but needed to be plugged a while longer lest they drop back down to ~90% after 10 minutes unplugged. We used an external battery pack to charge more gradually. On a cloudy/rainy day, we picked up a fair amount of charge from inside our double-wall tent. Not as fast, but I'd guess it'll charge a smartphone 0-100% in 12 hours.The nylon folder-like thing holding it seems a little too heavy for ultralight backpacking, but I admit the durability was nice. While flipping the panel over to plug things in, I had the panel scraping on rocks, and there was no apparent damage to the sleeve or panel. I imagine you could lighten the while thing up by cutting parts of the nylon off, but I might keep it on just for the durability and because I don't know where the wiring is inside. And it's nice to have some rigidity when stuffing this into a packed backpack and dragging it through horrendous off-trail conditions. The little string loops on the four corners are great for hooking to things to keep the panel from blowing over or blowing away in the wind. There are two USB plugs in the back. I suspect those will be the first part to fail.

First off I gotta say this thing will be a lifesaver during hurricane season in Florida. Very compact when folded up as well. Comes with 4 carabiner clips that clip onto the 4 sides of the panel to hold it onto a backpack or hang off a house or what have you.In my tests it seems to be able to charge a power bank at about 1000mah per hour of in the sun. Which doesn't seem like a whole lot but if that's all you have to be able to charge your phone you're gonna be glad you have it!Water resistant (IPX4 Rated) and I inadvertently tested this because it started pouring raining while I had it outside charging a power bank. It got plenty wet and still works perfectly fine. The power bank I had in the zipped pocket underneath didn't get wet like I thought it might because it's a mesh pouch but unless water puddles up underneath it you probably don't have much to worry about.Comes with a micro USB cable and 2 usb ports. I would've liked to have seen a multi cable included that had Usb-C and lightning on it but maybe they can implement that in the next version.One last thing is be careful when you pick it up and try not to touch the solar panels themselves. I picked it up by the edge with my thumb gripping one of the panels and I felt cracking below my finger. It doesn't seem to affect the panel but just keep that in mind.

Used this for 220 miles on the JMT. It is now a core part of my backcountry kit.I owned the 10W older version; this one with 2x USB 5V outputs is a nice upgrade. The integrated loops made attaching it to the top of my backpack easy. The zippered pouch and weather-protected USB outputs are very useful. The LED power indicator is nice. (Seems must be a decent capacitor inline, to smooth/maintain output during brief interruptions.)For long backcountry trips where I need to charge multiple devices (headlamp, Kindle, Garmin InReach, phone, camera...) I now carry 1x 10000mAh RAV or Anker USB battery bank; and this. I found I could charge some devices during the day and also recharge the battery bank, which could then e.g. charge my phone overnight.The only thing I am looking forward to ever-improving efficiency; lighter weight; and, I would prefer a fully water-proof version. I was unsure how wet this could get so didn't leave it out in the rain.Repeat customer. Will buy their products again.

Lightweight- it is smaller and compact, folding into itself nicely. Now i consider it lightweight but for someone counting ounces on hiking or mountain climbing, probly have to judge for yourself.Thickness (size): id say folded up its about half the size of the old “trapper keepers” (some may be too young to remember those) or half the width of a regular notebook but same height. Now unfolded it is a trifolded design so it gets a little wider but nothing that cant be managed. I use mine a lot on the dash of the suv for when im out riding my rzr rs1. I can keep things charged while gone. Simply unfold it and lay it across the dash, plug in the usb and device- done.Power output- i have used my inline usb multi meter on it when charging my then iphone 10 max and now my 12. Both phones have pulled the full 2.1 amps but could never get them to pull more than that even with a usb to usb-c adapter and a factory iphone usb-c charger cable. So to be fair, I am an electrician so I decided to solder on some leads to the end of the panels to bypass the usb output. I was able to test and see how close I could get to the advertised “20w”. I could pull 15 watts consistently but never the full 20. Now obviously I was not testing in a lab or anything fancy, but I did use a decent fluke multi meter. Not some cheapy. Could 20 be pulled from it, most likely. Me being in Indiana and maybe being off a degree or two on the sun angle (yes i looked up the appropriate angle for my zip code and used the iphone angle finder-geek) these are all things that play into the output.Cost and build-built fairly well with nice material on the outside. Not overly built but being retired from the service, it puts you in mind of the same material as the assault bags or backpacks just not as thick. As for cost, it comes in at a decent price point for the intended uses. I wasnt looking for a charge bank in this case. So some of my larger items to charge like my ipad or or kids tablets (kindle fire hd) etc. its hard to beat it. A charge pack will run dead before filling multiple tablets unless you spend some money. I also wanted something to work while away riding. Not to mention, (if some of you fear) that if id use a charge pack while out riding, the circuit doesnt cut off at low voltage and then the lithium battery catches fire. Then i come back to find my yukon in an ashy mess. So, eliminating one issue (charging is another potential, i know) and sticking to something that will continue to last and produce power after thousands of charge cycles for this price along with the other up sides, makes it a fairly decent purchase.Only real downsides i can find is that it would be nice to have an added usb-c to maybe pull more than 2.1amps like some newer phones will. And maybe add an option to some how sucker cup it to the windshield or a window in a house etc. this opens up soo many more uses. Then one can use it indoors to charge items and not have to leave it, along with the device, outside. Also dont have to find a way to prop it on the window ledge or if your not parked the correct way etc etc.

This seems to work great. Will keep my phone at break-even on a partly cloudy day. Actually charges a bit in continuous sunlight. With 13W you won’t be charging your Tesla. You won’t like sitting in the kind of sunlight it needs, so get a small power bank and set it out to charge whilst you sit in the shade.On a cloudy day you are SOL, so plan that in.It seems simple and robust but I don’t trust it to withstand even the first drops of water from the sky. I don’t think it will work well hung from a backpack like all the ads show, and plus the flatland dork factor is off the charts if you do that. And if you take a tumble you will trash it or lose it. Plan on keeping it stowed most of the time and only charging under optimal conditions, during lunch eg.Even with this: Do not rely on your phone for your map and compass unless you want to die.