5つ星のうち4.0A Comparative Practical Review of the Anker 21W and Aukey 20W Portable Solar USB Chargers
投稿者CompuForensics2015年11月25日 - (Amazon.com)
COMMON BASIS FOR TESTING I recommend that you review the accompanying video first. I purchased the Anker PowerPort 21 watt and Aukey 20 watt portable solar chargers within the last week. Neither was provided in consideration for this review.
The test was accomplished on a sunny nearly cloud free afternoon at about 1:30 p.m. Both three panel fold outs were arranged in nearly identical positions on a small table in my back yard. An inexpensive Drok LED USB tester was employed to measure output from both products.
Both products utilize SunPower solar panels, reputed to support conversion efficiency up to 23.5%. Both also include controllers to allow for the fastest possible charging speed up to 2.4 amps to each of two USB ports. Both employ canvas fabric and Pet polymer faced panels with a water resistant design; water resistance was not tested on either unit.
The 1 amp USB port was used on both products. Switching the meter to the other port did not produce additional power. The USB charging cable provided with the Anker product was used on both; a cable was not provided with the Aukey unit.
QUANTITATIVE RESULTS As shown in the video, the Aukey 20 watt product produced 5.15 volts at 0.51 amps for a total of 2.6265 watts. Power, measured in watts, is equal to voltage multiplied by amperage. While the output from one USB port should be substantially less than that from both combined, the substantially lower realized output is instructive. Both units consistently produced sufficient power to cause my 5 inch Android phone to reflect charging.
The Anker 21 watt product produced 5.11 volts at 0.52 amps for a total of 2.6572 watts. Despite being rated at 21 versus 20 watts, both chargers supplied about the same power to the Smart phone. I strongly suspect that both the Anker and Aukey solar chargers would have charged at a much higher rate had something more than a 5" Smart phone been used. In this regard, the same Smart phone only charged at 4.93 volts at 0.47 amps using the same Drok meter with a regulated power supply running at 13.8 volts into a vehicle USB charging port. That both the solar chargers charged the Smart phone at a greater rate than the regulated power supply would tend to validate the claim of both manufacturers that their solar chargers would charge at the fastest rate safely possible for a given device.
PHYSICAL PRODUCT COMPARISON & CONCLUSION Both products include metal clips and or fabric loops to allow easy attachment to backpacks or other objects. The Anker uses four metal eye holes whereas the Aukey has four fabric loops and a single metal eye hole. Both have comparably sized storage compartments and use Velcro to secure the foldout panels. Anker includes a red LED between the USB ports to signify charging. The Aukey additionally includes an attached rigid panel sized board for positioning of the panels.
The power output is sufficiently close to nullify that as a serious consideration. Construction and components are also essentially the same. Both appear to be of Chinese design and manufacture.
I believe both were worth more than what I paid for them, although the Aukey cost me $5 less. I did a fair amount of research prior to buying these products and believe both are deserving of excellent ratings. My technical video reviews routinely require at least a couple of hours to produce and I would appreciate a helpful rating if you found it so.
POSTSCRIPT Since some of you might be interested in seeing how the Anker Solar Charger did under a greater load, I placed the panels on the same table about 1:15 p.m., again with a nearly cloudless sky; the temperature was again about 50 degrees. This time, I added a 20 amp NewNow S25 USB storage device to the 5" Android phone. The storage unit is rated at 5 volts at 1.5 Amps input.
With the panels laying flat on the table, the Drok meter registered 4.64 volts at 1.28 amps (5.9392 watts). By lifting the panels more toward the sun, the voltage rose to 4.98 volts and 2.19 amps (10.9062 watts). Only one of the USB ports on the charger was used. The Aukey charger was not tested, but since it employs the same brand, quantity and size panels, I have no reason to believe the results under a greater load would have been substantially different.
POSTSCRIPT - STATING THE OBVIOUS
While there is no simple answer to realized solar panel efficiency, suffice to say that you are much more likely to achieve good results in Arizona than in New England. That is, panels located closer to the equator on a sunny day have far greater potential for producing solar electricity than the same ones closer to the poles. This is a function of radiance, the single most important determinant in panel efficiency. Obviously, radiance is much better on a cloud free day than an overcast one. Just as obvious, panels are also much more efficient if pointed at the sun,
For a much better understanding of solar panels, I suggest you consult UGov.Net, American Home Disaster Preparedness. Understandably, I'm not paid to do this and the site is clearly a work in progress.
5つ星のうち5.0Works for an iPhone even in a polar vortex
投稿者Steven Hughes2014年1月23日 - (Amazon.com)
-UPDATE 3/18/14- [Just because your iPhone/iPad/etc. says "Not Charging" when you plug this in doesn't actually mean it's not charging or not compatible. It just means it's not charging as fast as usual, but it probably is still trickle charging, which is fine. If you plug into this solar panel and get no response whatsoever, that's when I'd be concerned about not charging.]
For the price and output, this solar charger is unmatched. A lot of solar chargers require direct sunlight to charge an iPhone any significant amount. Standard iPhone wall chargers use 5 Watts. This solar charger can give you that much even on a bad day, and much more than that on sunny summer afternoon.
On the other hand, iPad Air wall chargers are 10 W, so you'll certainly need some good sunlight to achieve that much with this panel. But I was able to trickle-charge an iPad Air with about 3 W lying on the floor next to a window that was letting in low winter sunlight. I estimate 3 W because it was charging a bit faster than my PC USB port does (which is 2.5W) but it still wasn't enough to recognize the panel as a charger, which for the iPad requires 5 W I believe. Holding the charger up to the window made it surpass the 5 W mark because it instantly recognized that it was charging, and the percentage went up much quicker (still not as fast as the wall charger though). I can't wait for summer so I can use this outdoors to its full potential.
Anyway, I'd say this is definitely worth the price, even if you don't really need it on a regular basis. It will be handy in an emergency (specifically in conjunction with a portable battery charger) and it's quite a cool accessory to show your friends. It is well-built, folds up nice and small to fit in anything but the smallest of bags, and it has two outputs so you can share your clean, free juice with the world (or if you're like me, you have about 50 devices with USB charging cables). Now, if you'll excuse me, I need to rant.
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OK, I see a lot of people here confused about electricity. I am an electrical engineer, so please bear with me.
Power is measured in Watts, not Volts or Amps. Power is equal to Voltage multiplied by Amperage.
Energy is measured in Watt-hours. One W-hr is how much energy you have consumed if you have used one Watt continuously (or on average) for one hour.
Batteries are rated in Amp-hours. This rating, multiplied by the nominal operating voltage of the battery, will give you the maximum amount of energy in W-hr that the battery can discharge.
Battery charging is not an efficient process, meaning it will take quite a bit more energy (sometimes 2-3 times as much) to fill up your battery than it can actually give back upon usage.
Lithium polymer batteries charge up more quickly and efficiently when they are depleted than when you're just topping them off. With the wall charger, an iPhone can go from 0-80% in a couple of hours, but takes another couple hours to get to 100%.
Solar panels are rated at their maximum power point in ideal conditions. So, if you buy a 5 W solar charger, you will probably never get 5 W out of that thing unless you are using a solar concentrator.
All this is to say, in a perfect world, the 5.45 Whr iPhone battery could theoretically be fully charged by a 14 W solar panel in about 24 minutes. Obviously, there are many losses and limitations that make such speed and efficiency impossible. So, please don't complain about how this solar panel won't charge up your 10,000 mAh portable battery in four hours. You must do a little research and temper your expectations with these kinds of products, or you will just be sorely disappointed. The cool thing is, technology is always improving, so those losses and limitations will be reduced over time.
So you're thinking about trying solar energy? Get a little thrill by charging off the grid? This 14 watt portable panel is an entry level device often referred to as a "gateway" panel. Sure you'll get free solar energy, and yes, you will lower your carbon footprint. But be careful because the satisfaction of off grid charging can become a steady habit.
You'll start off with this little 14 watt panel and it will feel great. Then you decide you need a battery pack to store all the solar energy that's wasting when your phone isn't charging. That'll be fun for a while. You might even make some crazy vow to charge your cell phone off solar energy only. But that won't satisfy you forever.
Next thing you know you're getting the Instaspark 27 watt portable panel. Charging your cell phone and 12 volt devices off the grid and it's one heck of a ride. Spending less time with family and friends as you surf the web learning everything you can about solar energy. And then it happens... You invest in a hard core 200 watt 12 volt home solar energy system. Now you're sucking up solar watts like free cake at your neighbor's kid's birthday party. And it all started by experimenting with this little 14 watt portable panel.