Review on VITCOCO 16W Foldable Solar Phone Charger with 2 USB Ports & Display Function - Solar Charger | Ideal for iPhone, iPad, Android, Power Bank | Waterproof & Portable for Outdoor Camping by Elizabeth Morton

The bottom line is that this solar panel works as it should, but if there's one thing I've found it's that the tilt of the panel matters. This is so important that sub-optimal positioning can make it appear as if it is not working properly. This is a 29W panel and I was able to get pretty close in my initial testing. As you can see from my photos, just before noon in the bright Florida sun I was able to test the output at 16.1 volts and 1.75 amps... This is really close to the advertised specs as 16.1 volts x 1.75 Amps = 28.175 Di On a day with a less than optimal angle, I only saw about 21 watts (as you can see in my other photos, 1.3 amps and 15.9 volts). All of this is relevant because if you plan to use it as suggested in the description and hang it on a backpack, I think it's doubtful you'll get full power delivery. On the other hand, the USB output is smaller, so it's not as sensitive to angle adjustment. I saw a constant 5.22 volt record on the built in display regardless of the position of the sun. I couldn't take a picture of the built-in display while holding it up to the sun, so I snapped a few shots with a USB meter. Under load, the voltage dropped to 5.12V, but I've seen current readings as low as 1.49, which is really good if you're just charging phones. The entire panel with included carabiners and cable weighs just under 29 ounces, which is heavy enough for me. Consider taking it on a hike for less than 4-5 days. I can usually bring some batteries and just charge the phones in the evenings or something. However, I see where a longer hike could make this a must-have piece of gear. Especially since phones are becoming more than just phones. Now I use mine as a GPS navigator, map storage, compass, satellite, and I don't even carry a separate camera with me anymore. So yes, keeping it charged is becoming increasingly important.