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Bigblue 28w sunpower. How We Tested

Bigblue 28w sunpower. How We Tested

    Best Portable Solar Chargers of 2023

    Electronics are a part of the adventurer’s quiver of tools more than ever before. Thanks to efficiency advances and cost decreases in solar cells, portable solar chargers are finally proving to be a viable means of providing electricity outdoors. A backcountry user might carry a smartphone, GoPros, headlamp, tablet, camera, headphones, and PLB or GPS devices. A family on an extended weekend trip will likely bring multiple smartphones, tablets, speakers, laptops, electric lanterns, and more. Rafters, climbers, bikepackers, and mountain bikers on a weekend mission might haul out even more high-powered lights and GoPros, radios, and other electronic equipment.

    By harnessing the energy of the sun, anyone can charge their legion of devices rather than carrying physical batteries or draining the battery in their vehicle or camper. From portable solar chargers that can accommodate multiple devices during a family camping trip, to power banks that hold the biggest charge, to lightweight options for backcountry users that weigh under a pound, we reviewed top models to find the best portable solar chargers for most outdoor uses. Plus, we’ve got tips and tricks on how to get the most out of your portable solar panels, power banks and chargers.

    We create reader-supported, objective gear reviews that are independently selected by our editors. This story may contain affiliate links, which help fund our website. When you click on the links to purchase gear, we may get a commission, without costing you an extra cent. Thank you for supporting our work and mission of outdoor coverage for every body! Learn more.

    Portable Solar Chargers Comparison Table

    We had three clones to evaluate, all of which performed similarly well, so it was hard to determine which of those to award. However, one did surpass the others, as various sites have mentioned. We also considered different use cases in making our final judgments. As such, some of our winners are in unique categories.

    Overall Winner: Big Blue 28W USB Solar Charger

    Weight: 1 pound, 5 ounces

    Solar Cell Output Capacity: 10 watts

    Power Output to Device: USB, 5V up to 2A (28W max)

    Foldable: Yes

    Integrated battery: No

    Ports: 2, 2.4 Amp USB-A Ports

    What we liked: simple, lightweight, provides more power than similar models, can charge multiple small devices, includes anmeter

    What we didn’t like:

    We concur with many review sites and consumer reviews that the 1 pound, 5 ounce Big Blue 28W USB Solar Charger was the best for most outdoor use. It’s a simple, lightweight, and powerful solar power charger that seems to provide a little more power than its competition. It will also provide enough power in direct sunlight to charge multiple small devices for one or two people.

    The Big Blue unit we tested also included an ammeter, which displays the amount of electrical current the solar panel is generating, setting it apart from the competition. That allowed us to see that the device was working and how much energy it was producing.


    Other than that, we found that it was remarkably, if not eerily, similar to two other top-rated solar chargers we evaluated. All three (the Anker 21 Watt PowerPort Solar charger, the Nekteck 28 Watt solar charger, and the BigBlue 28W USB Solar Charger) use the same basic design with two USB-ports and a light to indicate that they’re getting a charge; the Big Blue’s light indicator is the ammeter.

    The solar cells in these foldable units are encased in PET polymer and surrounded by polyester canvas. Each offers moderate IPX4 water resistance — although you don’t really want to use these devices in the rain anyhow. They’re so similar they even use the same solar cells — SunPower’s Maxeon solar cells — which are among the most efficient commercially available solar cells and can convert up to 25 percent of the sun’s energy.

    Each of these solar chargers had metal grommets in the casing, which allows you to attach them to a rock, backpack, tent, or camp chair. Each has a pouch where you can store the devices being charged and cords for charging your devices. None had kickstands or means to orient them to the sun properly, so you’ll have to get a little more creative, like propping them up on a rock, attaching them to your tent, or attaching them to your backpack to orient them properly to get the most power out of them in camp.

    The Big Blue did better than the competition in tests, producing just under 950 milliamp-hours (mAh) of energy in an hour. In relatively similar conditions, the Anker produced 733 mAh, and the Nekteck produced 834 mAh. Without a dedicated test facility and control environment, it is hard to offer a complete scientific evaluation of the differences between these three since clouds could have obscured the sun for part of the testing periods.

    In our experience, the Big Blue (or other similar solar panels) will integrate best into your outdoor lifestyle with the help of an external battery, like the Anker. The solar panel charges the battery, and then the battery provides a steady charge to reliably and safely charge your phone. See our section below on batteries for more details.

    The Big Blue offered the highest power output among these three, and its cost is essentially the same as the Nekteck, so The Big Blue edged out the Nekteck as the best solar charger. It’s easy to use, well-priced, and offers enough portable power to charge a backup battery. Best yet, it is rugged enough to last for years.

    Interested in backpacking gear? See our Backpacking section for our most popular stories.

    Honorable Mentions

    Both the Anker portable charger and Nekteck portable charger fell a little short of the Big Blue, our overall winner (see review above). Either offer a great value, but we think the Big Blue has the most to offer for the money.

    Anker 21 Watt PowerPort Solar Charger

    Weight: 14.7 ounces

    Solar Cell Output Capacity: 21W

    Power Output to Device: 21W to device via USB

    Foldable: Yes

    Integrated battery: No

    Ports: 2, 2.4 Amp USB-A Ports

    The now discontinued Anker 21 Watt PowerPort Solar Charger may no longer be available, but we think it’s worth putting on your radar for a few reasons. First, it’s a near-clone of the Big Blue (see review above), our overall winner, so it’s a good example of the similarities between solar panels on the market. Second, it is still widely available on sites such as ebay for folks interested in buying a used solar panel.

    One difference is that it was slightly smaller and lighter (15 ounces) than the Big Blue. The Anker produced a little less power in a given time in similar conditions, as expected. Its charging pouch also had a hook-and-loop closure rather than a zippered closure like the other clones. It didn’t include an ammeter. Ultimately, even when the Anker was available, we found the Big Blue to be a better choice given the amount of power it generated.

    Nekteck 28 Watt Solar Charger

    Weight: 1.44 pounds

    Solar Cell Output Capacity: 28W

    Power Output to Device: 28W via USB

    Foldable: Yes

    Integrated battery: No

    Ports: 2, 2.4 Amp USB-A Ports

    Without the branding, from the outside, the Nekteck 28 Watt solar charger is essentially indistinguishable from the Big Blue. our overall winner (see review above). The specs are similar. Opened up, and without the ammeter, they look essentially identical, too.

    However, in the end, it didn’t perform quite as well as the Big Blue — even though it uses the same solar cells and design. In relatively similar conditions, the Anker produced 733 mAh, and the Nekteck produced 834 mAh. It also has a claimed weight of 1 pound, 7 ounces — two ounces heavier than the Big Blue.

    BigBlue 28W Solar Phone Charger Review

    If you go camping often and you have a phone that drains its battery fast like me, then check out my real life BigBlue 28W Solar Phone Charger Review below.

    Please keep in mind that links in my posts are affiliate links. As an Amazon Associate I earn from qualifying purchases. If you go through them to make a purchase, I will earn a commission. Earning commissions enables me to write, manage and maintain this free blog for readers like you.

    The Problem

    When I go dry camping (no hook ups for water, sewer and electricity), I rely on my gasoline generator to provide power for our needs. We only turn the generator on for a couple of hours in the morning and at night so we can use the hair dryer, television and other appliances that require current from the 110 volt receptacles. Our trailer batteries don’t power the 110 volt receptacles, only the water pump, water heater, furnace, etc.

    So, my wife and I always have to remember to plug in our phones during those Windows of time when the generator is running to charge our phones. Sometimes our phones don’t get completely charged, which is an issue if the phone batteries don’t last all day. So, I decided to buy a portable solar panel to power my phone and other electronics when camping.

    My Choice

    I did a lot of research online and landed on the BigBlue 28W Solar Phone Charger with Digital Ammeter. The reviews were overall good for this solar panel and that the manufacturer provides a 2 year warranty.

    Seller’s Specifications:

    • Output: 2 USB ports so you can charge two devices at one time.
    • Built-in Ammeter: The ammeter can measure the current in a circuit. The value of Amps of our 28W solar charger depends on your devices, sunlgiht intensity and cable used.
    • SmartIC Technology: With the built-in intelligence chip, the solar phone charger can detect type of device then deliver its fastest possible charging speed.
    • High Efficiency: SunPower Solar Panels with high solar conversion efficiency by up to 21.5% – 23.5%.
    • Compact size and lightweight: 11.1 × 6.3× 1.3in folded and 21.0 oz
    • Special PET Polymer Surface: Industrial-strength PET polymer fabric protects the solar panel from occasional rain or wet fog. IPX4 waterproof level, but the USB ports and ammeter are not water-resistant, so keep them away from water while charging.
    • Accessories: USB cord and 4 clip hooks that help you hang panels anywhere.

    BigBlue 28W Solar Phone Charger appears to be sturdy and is very easy to use. I tested it on one of my phones as soon as I unboxed it. It was easy to use, I just removed the packaging, plugged the solar panel into my phone, then placed the panels (not my phone) on the ground in direct sunlight. I would recommend covering your phone to protect it from direct sunlight while charging.

    Below are charging results. I wanted to leave the solar panel out until my phone was fully charged, but some clouds moved over my house and it appeared it was going to rain so I stopped testing it.

    Start Time: 10:35 am – Phone battery was at 17%

    bigblue, sunpower, tested

    End Time: 11:40 am – Phone battery was at 51%

    So, the panels charged my phone 34% in 65 minutes in full sunlight. As a result, I assume that to charge my phone from 0% (which I don’t believe you should ever let your phone battery level go that low before charging) to 100% it would take probably around 3 hours in direct sunlight. Not too bad. If you have two devices plugged into the solar panel, then it make take longer to charge. Results may vary depending on where the sun is in the sky and if there are any clouds and how you lay out the panels.

    So, I could leave the solar panel on my car’s dash board during lunch time to charge up my phone. Or, I could hang the panels on my backpack while I’m hiking.

    I also tested the solar panel with a small battery bank. Note, the sun was not full direct sunlight, there were clouds in the sky so the full direct sunlight was intermittent.

    Start Time: 9:15 am – Battery bank had one light (0-25% charged)

    End Time: 1:57 pm – Battery bank had four lights (100% charged)

    So, the solar panel charged my battery bank in about 4 hours and 45 minutes with intermittent full direct sun. Note, the battery bank is a 10,000 mAh battery, whereas my phone has a 5,000 mAh battery.

    I like the small portable size and the fast charging speed. I’ve seen reviews on other brands of solar panels where the solar panel takes all day to charge a phone, so I was pleasantly surprised how fast the panel charged my phone. As always, I’ll provide an update here if I run into any issues or quirks. Happy camping!


    Whoops. If customer service ever contacts me and replaces the unit, I’ll be a happy camper, until then, this lack of support is dragging down this review. Edit: May 31, 2019 Ibigblue support returned emails and made it right. Their willingness to fix the situation while I am on my road trip and cannot just return the item to Amazon has earned them two stars back

    Is that a deal breaker, no. I have only used it to charge external battery packs and it has no issue charging 18200 mAh RavPower external battery pack. I’m not sure if the slight warp is normal, but it has not impacted the overall performance. It does need full sun (expected) and it does take hours to charge a device (also expected)

    Charging Time

    8, and it charged in less than two hours along with the power bank. This was using a short charging cable with the tablet in the shade. Don’t leave your devices in the direct sun. I’d generally recommend not using the zipper pouch in most cases too

    Charging indicator (⚡️) flashes on and off showing irregular connection, even if using an Apple charge cord that works well on other power sources. It may be I just got an anomaly, as the other positive reviews tend to indicate. But I can only give a review based on our experience with it, which has been frustrating.


    In my testing, each port supplied up to 2.4 A at a time, but the voltage was down to 4.15 V at that load. It supplied 4 A when drawing 2 A per port, but the voltage at both ports dropped to around 3 V, which may be too low to charge

    After sitting in the sun for a while and getting warm, I was only able to get about 15 Watts from the panels. The voltage regulator is a simple buck converter used to bring the voltage down to 5 Volts. The converter seems only be able to output about 12 Watts reliably, any more than that and it seems to trip a thermal cut off that limits the output. So, ultimately this is a 12 Watt solar charger

    Performance: Between the lines

    As unfortunately tends to be the case with many products, the specifications listed within the headline of the BigBlue Solar Charger product page is a bit misleading. BigBlue states the solar charger is 28 watts, and while technically true, that’s not the output it delivers.

    As explained by BigBlue in the fine print of the product description, the unit features four seven-watt panels, which makes for a total of 28W. However, the actual power output is dramatically lower, due to the conversion process from solar energy to actual deliverable energy over USB. BigBlue clarifies that ‘under ideal conditions’ the solar charger can output a maximum of 17W (5V3.4A).

    With this more nuanced (and accurate) information taken into account, I went about testing the unit under various lighting conditions to see if it would perform as detailed in the product description. In my testing across various sky conditions, the unit performed right on par, maxing out at just under 17W in direct sunlight on a perfectly sunny day (when using the two 2.4A ports). Even in less-than-ideal lighting situations, such as a cloudy day with snow on the ground, I was able to achieve 10W output (when using both 2.4A ports).

    Precisely how fast your device charges will vary depending on a number of variables: ambient temperature, device temperature, location of the sun in the sky, clouds, and, of course, the battery capacity of the device you’re charging. That said, output proved consistent when taking into account the variables I (and Mother Nature) threw the solar charger’s way.

    Price: Great value

    With a suggested retail price of 70, the BigBlue Solar Charger is right on target with similarly-specced units. Yes, it’s not the 28W charger as somewhat deceivingly advertised, but it still packs a punch in the right conditions and its ability to withstand the elements makes it a great choice for hikers, campers, and survivalists alike.

    I also enjoyed knowing the device could take on the elements while continuing to charge my devices. When my smartphone was secured inside the included and plugged in, it had no problem taking on the moisture and charging (albeit slowly) in snowy and rainy environments. I wouldn’t count on charging my devices on the daily, but I’ll definitely be taking it with me on my next camping trip and keeping it in my emergency road kit in the meantime.

    Even in less-than-ideal lighting situations, such as a cloudy day with snow on the ground, I was able to achieve 10W output (when using both 2.4A ports).

    At 70, it’s a small price to pay for that extra level of comfort knowing I’ll be able to keep my devices at least somewhat charged during the day if my phone’s battery runs out and I don’t have access to any power port.

    BigBlue Solar Charger vs. Ryno Tuff Solar Charger

    One of the most direct comparisons to the BigBlue Solar Charger is the Ryno Tuff Solar Charger (see on Amazon) With a suggested retail price of 75-80, it’s nearly the same price as the BigBlue Solar Charger. On top of that, the Ryno Tuff Solar Charger is also waterproof, has a higher maximum output of 21W, and features a built-in 6,000mAh power bank, so you can save up power for a time when light is a little more scarce. Overall, the Ryno Tuff may be the better option for most people, especially due to its built-in power bank.

    A solid, budget-friendly portable solar charger.

    When all was said and done, I was impressed with the performance of the BigBlue Solar Charger. Calling it 28W in the product listing’s headline is incredibly disingenuous, but if you read carefully and understand it will max out at only 17W, it’s easier to recognize the solar charger actually lives up to its specifications. It’s a bit heavy for ultra-light hikers, but at roughly a pound, it’s still light enough to justify in situations where you need to power a few mobile devices, be they smartphones or GPS units.

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