S14 Dual Port Solar Charger, Extremely Durable and Reliable, Waterproof, Auto-Retry, Quick Charge Smart Phones, Power Banks and Many Other USB Devices

I have several different solar chargers. This one is different from any of the others in several ways.1. The construction is water resistant (the electronics) and the panel itself seems to be water proof. The cells are mounted and sealed onto some kind of hard synthetic board, possibly fiberglass.2. The charging electronics include one port with an "auto re-try" feature. Sometimes when a cloud passes over the sun, the output voltage of any panel drops until the device you are charging says "accessory not supported" or some such and will refuse to resume charging even when the sun comes back out. This feature interrupts power to the device every so often to reset the device and make it take a charge again.3. Rather than being sewn into nylon to form the complete panel array, the two leaves of the panel are joined by a plastic "hinge" which has two metal contacts embedded into it, joining the cells on both panels together. I was concerned about this hinge and the bending of the metal strips. We all know what happens when you bend a strip of metal too many times, it snaps. However, it turns out that the plastic hinge is actually the material that covers both the front and back of the panels bonded together where it covers the gap between. This means there is no joint to fail. Also, I contacted Suntactics and they informed me that the metal strips are called flex circuits, the same ones used in flip phones. I looked these up and found references to them being able to flex over a million times without failure. Don't think I'll be folding this panel quite that many times. Also, Suntactics informed me that in all the thousands of panels they have produced, they have only had two hinges break, and that was due to abuse. If there is an issue with the hinge, they have a no-hassle guarantee.Now, as for performance, the closest panel I have to this one with approximately the same output is the RAV Power 15 watt panel so that is the one I compared the Suntactics to.On a day with the sun shining through light haze, the Suntactics produced 4.97 volts and 1.18 amps while charging a Sony 10,000 mah battery bank. At the same time, the RAV Power 15 watt panel produced 5.21 volts and 1.27 amps while charging the same battery bank. This means the RAV panel produced 6.61 watts compared to the Suntactics which produced 5.86 watts. The RAV produced 12.82% more power. However, the RAV also has 153 square inches of solar cell surface area compared to the Suntactics which has 120 square inches. That is 27.5% more surface area.What does this all mean? It means that the Suntactics produces less power than the RAV Power 15 watt panel, but is more efficient. With 27.5% more surface area, the RAV was only able to produce 12.82% more power. To me this says that either the solar cells used by Suntactics are higher quality than the RAV or the way Suntactics uses them is better. This opinion was backed up when I took both panels out under overcast skies. The Suntactics produced 4.18 volts and .29 amps while the RAV produced 4.14 volts and .26 amps. That is the greater efficiency coming into play. It is also lighter and more weather resistant. If it gets caught in a downpour, the waterproof construction will shrug it off. The RAV, assembled with foam padding, nylon and an unknown backing material would become soaked and I don't know how long it would take to dry out and if it would still work when it did. Finally, the Suntactics is made in the USA, which is very important to me.In conclusion, I am very happy with the Suntactics. It is a well made tool that I will be using when lightness, toughness and reliability are critical. I can see no reason why you shouldn't choose this panel. Also, they stand behind their product.Update 12/19/16 As with the scharger 8 which I also own, I wanted to test this panel out at the solstice.When the sun is at it's current low angle in the sky the amount of solar radiation we receive at 43 degrees north is a fraction of what it is in June. Yesterday the sky was very clear with very low humidity and a temperature of -4 degrees fahrenheit. This panel was able to produce 4.89 volts and 2.04 amps while charging an ipad air 2. I did the test at 11am. Even at the solstice, this panel is able to charge at the same, if not slightly better, performance as the wall brick the ipad came with. If you are wondering if this panel can work year round, the answer is a resounding yes!Update 5/10/17 After hearing about all of the weather disasters around the country lately, it occurred to me that Suntactics suggests disaster preparedness as one of the reasons to buy this panel, but would it do any good in the areas suffering storm after storm? How much would they even see the sun? As you can see in the picture, yesterday was a completely overcast sky, not even a bright patch to show the sun's location. I put this charger up on the roof, pointed it south and plugged in a completely depleted guide 10 plus with four eneloop AA batteries in it. Despite no direct sunlight at all, the flashing red charge indicator came on. I checked it after 5 1/2 hours and the solid green light indicating full charge was on. So even in bad conditions, it took somewhere less than 5 1/2 hours to fully charge four AA batteries. At 5:30 PM with conditions lightening up a bit (still no visible disk of the sun, but an occasional bright patch in the clouds) this panel charged an iphone 6s from 10 to 37% in one hour. The guide 10 plus with the AA batteries then topped off the phone to 100%. Then it charged a sandisk wireless flash drive. Then ran a usb stick light for 30 minutes. Then topped off the phone again from 93% to 100% while streaming video for 25 minutes before the red light came on and it was fully drained again. So, YES. This is a very good thing to have in an emergency. It will not put food and water in your mouth, but power can be critical to have. A Li Ion battery charged by this can run your phone for a long time and a usb light for even longer. AA batteries charged by it can power flashlights, GPS', walkie talkies, backpackers UV water purifiers and a host of other things. Last, but not least in my opinion, it can power your mobile device for a little entertainment. That might not seem important in an emergency, but moral is very important too. FEMA suggests having three days food and water stored away (which seems too little to me) and I would very highly suggest that you need one of these panels as well. They are very handy for fun and could be a lifesaver when things are less fun.

actually a good quality

When I looked at various solar power options, the S-14 came out on top because: a) it doesn't include a built-in battery, and b) it generates a lot of power. Not having a battery allows it to be smaller and lighter, and avoids the problem of battery failure. (The surest killer of rechargeable batteries is excess heat, and guess what: the sun generates a LOT of heat.) You can always get a USB battery if you want to charge a battery with it.It's worked great and I'm very happy with my choice. It's light weight, well-constructed, fairly small, and it generates plenty of power.It has two ports, the A ("Auto") and the M ("manual") ports, and the manual suggests that Apple products prefer the Auto port. I'd advise you to experiment with the M port first, then the A port if that's not cutting it. My iPhone 5 charged fine through our front windows on an interimttent-cloud day, using the A port. My older iPod wouldn't charge (through the windows) on a full-sun day. I switched the iPod to the M port and it charged just fine. So don't get fooled into thinking that A is better than M or necessarily works better for smart (or Apple) devices. They work differently and depending on the conditions (through windows, outdoors, partly cloudy, sunny, intermittent clouds) and the device (older, newer, smarter) one may work amazingly fast and the other doesn't accomplish much.There is a definite drop off if you use it through windows instead of outdoors, and combined with the fact that it's harder to get a good angle to the sun and keep shadows off of it through a window, you need to have reasonable expectations for indoor use. I can charge my iPhone 5 through windows (direct sunlight, mid-May, DC area) and I can even use it as a Personal Hotspot for my iPad and the sun keeps it topped off. As long as I keep it fully in the sunlight, no need to worry about optimal aiming. On the other hand, tablets need more juice, so I can only charge my iPad Retina if I leave it totally off while its charging. (For reference, when I use a stand so that I can position it for best sunlight through our windows, on a sunny morning (10 AM-ish) in Washington DC in late May, the iPad Retina charges about 10% per hour.)Outdoors is much better, of course. I tried using my iPad Retina while charging outdoors under the same conditions, and it appeared to roughly be breaking even. (I was browsing the web, etc, using Wi-Fi, with the panel held out the window.) I wasn't patient enough to see if it was slowly charging or slowly draining, but it stayed at the same percentage charge for quite a while.I'm not a camper -- I mainly want something to charge stuff around the house, to use when I'm in the park, and to take on some international travel. This fits the bill perfectly.

They said this solar charger should work even on indirect sunlight but it doesn't. It won't charge my phone, my backup battery nor my tablet individually. Sometimes, it even discharges the device in auto or normal mode. I tried for a week and have not had even one successful charge.Charging scenario: The solar charger was placed by my window that has most sunlight towards the afternoon. It was sunny for that whole week.

I am sure it doesn't work indoor through window under the sun light.I tried outdoor too. It shows the phone was charging, but iPhone's battery was keep reducing from 25 to 23% in 5 minutes.I was going to use it for traveling in between airports. Now I am not so sure about this idea.