May. 06, 2024
Read more OVERALL REASONS TO BUY Small and efficient Does better on cloudy days Inexpensive REASONS TO AVOID No kickstand legs 20.9 oz |28 watts The BigBlue SolarPowa 28 is our top choice for a portable solar charger because it performs the best for its size in solar charging efficiency. This panel balances portability and solar charging efficiency the best of any solar panel we tested. This model has impressive solar charging abilities in both direct sunlight and during cloudy days. And it weighs less than all but the smallest 5-watt panels. It unfolds into four solar panels quickly and easily, and it's light enough to prop up or hang off of just about anything to get an ideal charging angle to maximize efficiency. When your portable electronics need a charge, this panel delivers it more consistently than any other. It does better than most panels on cloudy days and has three USB-A outputs, so you can charge multiple devices simultaneously. When you're done charging, this solar charger folds into a small enough size to fit in just about any backpack. It closes with velcro and has a pocket where you can store charging cables, a battery bank, and other accessories. This is a great all-around panel for charging all your small electronic gadgets. One downside to the BigBlue SolarPowa 28 is that, though it's relatively lightweight for the 20-40-watt panel class, it makes some sacrifices in usability to be as light as it is. We found that all of the panels we tested perform best when they can be angled directly at the sun, and this panel doesn't have kickstand legs to easily get that perfect angle. Weighing in at 20.9 ounces, it's lighter than most of the other panels in its class, but we would be okay with a few extra ounces for that extra usability. It is light enough to easily prop it on a rock, and it has carabiner clips to help prop it up, too. But this panel could be improved with a couple of fold-out legs. This is still a great solar panel overall and performs better than most other panels we tested in every category. This is the panel we'd choose for most applications where we want reliable solar charging, in an impressively small size, at a very affordable price. Read more: BigBlue SolarPowa 28 review The SolarPowa 28 balances solar charging efficiency and size better than every panel we tested. Credit: Sam Schild OVERALL REASONS TO BUY Good charging speed Easy to hang Great value Lightweight REASONS TO AVOID Hard to reach pouch makes the panel lay crooked 21.1 oz |20 watts When you're outside in the sun, having a panel that charges quickly is key. The X-Dragon 20W comes at the lowest price with the most watts of any solar charger we tested. This 20-watt solar panel provides reliable, fast charging speed, almost as good as more expensive options, all at a reasonable price. The high conversion rate made the panel efficiently charge on sunny days better than most others, and it performs relatively well on cloudy days, too. It has two USB-A outputs that can each put out up to three amps, which is enough power to charge any USB device. Roughly the size of a notebook, this solar charger unfolds into three panels and has a zippered case that can easily hold two charging cables, a battery pack, and more. Though the zippered pouch on the X-Dragon 20W makes storing your charging cables easy, it does make it harder to lay this panel completely flat on the ground. There is a canvas flap that secures on top of the mesh zippered pouch. This flap, along with the pouch, makes it so the panel sits at an awkward angle when you try to lay it flat. This isn't a huge deal, and it's easily fixed by propping it on another object, but all that extra material under one of the three panels makes it harder to deal with. But, if you're looking for an affordable solar panel to charge on the go, we think this is an excellent affordable choice for a portable solar charger. Read more: X-Dragon 20W review The X-Dragon 20W is a great value for a 20-watt portable solar panel. Credit: Sam Schild OVERALL REASONS TO BUY Folds and unfolds quickly Portable size Fast DC charging Multiple USB charging ports REASONS TO AVOID Quite heavy Nothing to protect charge controller and outputs 47.25 oz |40 watts The FlexSolar 40W is a high-output model that easily unfolds from the size of a large book into six solar panels. If you're looking for an easy-to-use solar charger setup that doesn't sacrifice wattage, this is our top choice. This doesn't have any velcro, magnets, or other clasps to deal with when folding and unfolding this panel, which makes it very easy to set up. And it's just as easy to take down when you're done charging. It has a DC output, which is capable of putting out 19 volts of power, so it's capable of charging portable power stations. It also has USB-C and USB-A charging outputs for your devices. We found during testing that the DC output on this panel could charge a 240-watt-hour power station faster than any other portable panel we tested with a DC output. It puts out an impressive amount of power while remaining relatively portable. While the FlexSolar 40W does fold down into a small enough package, it's not nearly as light as some of the other portable solar chargers we tested. At 2 pounds 15.25 ounces, it weighs over twice as much as some other panels in the 20-40 watt range. However, it also weighs less than most 50+ watt panels we've tested, so it's more portable than a lot of solar panels out there. It lacks a cover for the DC and USB outputs, which is a weak point in terms of durability, but perhaps its only weak point. After extensive testing, we haven't had an issue with these exposed outputs, but it's certainly worth noting. This portable panel also comes at a very affordable price, considering it's a 40-watt panel that stows away quickly, and it's certainly worth considering for all your solar charging needs. Read more: FlexSolar 40W review The FlexSolar 40W features six panels that fold up quickly and easily. Credit: Sam Schild OVERALL REASONS TO BUY No folding necessary Ultra-thin Lightweight Kickstand leg for sun angle REASONS TO AVOID Only one USB-A output No integrated cable storage Not the fastest charging 12.35 oz |5 watts The Goal Zero Nomad 5 is our top pick if portability is your top priority. This panel is small enough to take backpacking. It's incredibly thin and remarkably durable. Plus, it weighs well under a pound. This panel weighs less than many larger battery banks that you might otherwise bring on an extended trip, so it could feasibly save you weight in your pack. It doesn't fold but is thinner than average and has a single kickstand leg to angle it at the sun. This lets you maximize the efficiency of this 5-watt panel in a way that's much easier than it is with other small solar panels. The Nomad 5 doesn't charge the fastest, but that's to be expected with a 5-watt solar panel. This is designed to charge a single small device, such as a battery bank. It only has a single output for this reason. Also, this panel doesn't have a place to store a USB cable, but if you're prioritizing packability, then you'll appreciate the fact that this doesn't have extra stuff that you won't use anyway. If you're looking for a super portable solar charger for the backcountry or something small, affordable, and durable for your daily life, this is worth a look. Read more: Goal Zero Nomad 5 review The Nomad 5 features a single incredibly thin panel that is super portable and works surprisingly well at generating solar power Credit: Sam Schild REASONS TO BUY Great value Fast charging Easy to use Light REASONS TO AVOID Large form factor 10.3 lb |100 watts In our lineup of the best solar panels for camping, we look at larger panels. The Jackery SolarSaga 100 continues to be both the best overall and one of the best value panels we've tested. This 100-watt solar panel is significantly more affordable than its competitors, user-friendly, lightweight, and performs well in both full and partial sunlight. It is the most efficient at rapidly charging electronic gadgets of any panel we evaluated, regardless of the weather. The SolarSaga instantly folds into a compact size and weighs only ten pounds which is light compared to similar wattage panels. The straightforward fold-in-half construction makes it very easy to transport it in your vehicle to take with you wherever you roam. The handle makes it easy to transport throughout the campground. You can swiftly deploy its fold-out legs to position it squarely at the sun and get the most out of its rays in the morning and evening. It has USB-A and USB-C ports and a DC output to connect directly to devices or an external battery. A built-in pouch with a zipper on the device's rear provides convenient storage for the hardwired DC charging cable and USB ports. It's a wonderful addition to your solar camping setup or if you want to have an off-grid backpack. Although it's light and folds into a small footprint, the SolarSaga 100 only has a single fold in its design. Because of this, its folded size is significantly larger than some of the other high-wattage panels we examined. This is your panel if you want a high-capacity solar panel that offers excellent overall value for your upcoming camping trip. Read more: Jackery SolarSaga 100 review The Jackery SolarSaga 100 makes it simple and fast to charge electronic gadgets using sunlight. Credit: Sam Schild 84 71 70 63 58 54 52 40 35 31 30 28 With competitive price and timely delivery, BEBEST sincerely hope to be your supplier and partner.Best Overall Portable Solar Panel
BigBlue SolarPowa 28
SCORE
Best Value for a Solar Panel
X-Dragon 20W
SCORE
Easy Six-Panel Setup
FlexSolar 40W
SCORE
Ultra Portable Solar Charger
Goal Zero Nomad 5
SCORE
Best Larger Solar Panel
Jackery SolarSaga 100
Weight: 10.3 lb | Panel Size: 100 watts
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Best Overall Portable Solar Panel $70
Best Value for a Solar Panel $57
Easy Six-Panel Setup $105
Ultra Portable Solar Charger $60
Flex Stacked Lithium Battery | More Power, Shorter Charge ...
Keeping base camp charged with only the sun.
Credit: Chris McNamara
We've been testing portable solar chargers and panels for years and have put well over 100 individual products through our comprehensive testing process. With each new round of testing, we carefully select the most interesting, most popular, and most promising models and purchase them at full price. Then, we test each product objectively and thoroughly. During testing, we look at how quickly each model charges with different amounts of sunlight, how it handles multiple devices at once, the rate of charging, and its portability, durability, and overall useability. To test our metrics, we used each contender in the field and tested them in our backyard home lab. See additional details on our testing processes in our How We Test article.
Our portable solar charger testing is divided into four mutually exclusive metrics that are weighted according to their overall importance:Our portable solar charger testing is divided intothat are weighted according to their overall importance:
Our solar testing team is spearheaded by Review Editor Sam Schild. Sam is a lifelong outdoor adventurer and off-grid explorer. Over the decades, he has spent thousands of nights under the stars, far from any power outlets. Sam has powered his bicycle rides across the country — more than once — and is a seasoned thru-hiker with numerous long-distance trails across America under his belt. He uses solar panels to keep himself connected to friends and family no matter where he roams, whether on his own two feet or with the aid of a pair of bike tires. Over years of using many iterations of solar panels and continually improved solar charging technology, Sam is intimately acquainted with the benefits and limits of powering devices from the sun. He tests solar panels large and small for GearLab, based out of wherever his feet are in the American West and Southwest.
Also joining our testing team is James Lucas, a long-time writer, editor, and photographer. As an avid climber who authored the Yosemite Valley Bouldering guidebook, you can find James outdoors more days than not. He spends his time documenting the outdoors and gear testing in Boulder, Colorado, and on frequent travels to California's Sierra Nevada mountains. James frequently uses solar panels to power his adventures and charge his camera gear when working out of his van in the Rockies and when perched atop sunny El Capitan in Yosemite.
We tested every panel side-by-side in the field and the lab to measure power output, weight, ease of use, and more.
With the growing solar market and all the technical jargon, it can be confusing to figure out what to buy. We will start by saying it can often be worth it to purchase from a reputable company with a clear warranty policy on its website. That way, if you end up with a dud, you can hopefully get your money back or a replacement.
We realize this can be confusing, so we're here to break it down for you. Watts (electric power) and amps (current) are two common units you will see listed for these products. Amps can be thought of as the amount of electricity moving through a given system. Volts can be described as the pressure that electricity is flowing with, think pressure exerted in a water hose. Watts is the cumulative power output from amps and volts that measures how much power and consumption you are drawing. Therefore higher wattage devices should deliver more power and charge devices faster, under the assumption the device is compatible with the amps and volts requirements.
A basic understanding of solar charger terminology goes a long way in making an informed purchase decision.
Credit: Chris McNamara
Once you get an idea of charging capacity and your intended use for a portable solar charger, it's time to figure out what devices you plan on using. For smaller handheld items such as smartphones, a portable solar charger with five to fifteen watts should suffice. For those hoping to charge larger items such as laptops or multiple devices at a time, higher wattage panels with twenty to fifty watts of power are recommended. Factors such as duration of use, amount and intensity of sunlight, and how often you plan on charging your devices all play a significant factor in how quickly and efficiently your devices will charge.
The size will often be relative to output and charging capabilities. Deciding on the right size will depend on the type of use and trips you plan on using your solar charger for. Someone who plans on taking backpacking trips and just needs a little extra reassurance to charge their GPS device will want something small and light. For those who have the space and need a solar charger while on work trips or weekend outings, a charger with a bigger footprint will be best suited.
Picking the right size solar charger comes down to charging needs and size preference.
Credit: Sam Schild
The amount of sun exposure and sun intensity can have a significant impact on charging. Consider the type of areas and climates you plan on spending time in. To produce peak charging efficiency, solar panels need adequate sunlight. Make sure to place your panels in ideal locations to capture sunlight and avoid running out of juice sooner than expected. Features such as kickstands and legs can help create a more optimal angle for charging.
Choosing the right location for your solar charger can make a big difference in charging capabilities.
Credit: Sam Schild
We also chose the best, most popular, and most promising portable solar panels on the market today to test side-by-side in this review. We tested every model in the same conditions to see which ones provide the most power and which are the most convenient to use. Whether you are looking for a solar setup for car camping or a compact charger to power your smartphone and GPS devices on a backpacking trip, our review offers excellent recommendations for anybody.
Dozens of companies produce affordable, effective monocrystalline panels ranging from small 5-watt models to more substantial, powerful options that will allow for a faster charge. Generally, the larger, higher-watt panels are going to cost more but will charge your devices faster and more efficiently.
The BigBlue SolarPowa 28 offers some of the best value overall. This 28-watt solar panel charges devices quickly, is portable, and costs less than many other panels that don't work as well. The X-Dragon 20W is also a great value. It costs less than any other 20-50-watt panel we tested but still works well to convert solar energy into electricity. The Goal Zero Nomad 5 is a less-powerful, 5-watt panel that won't charge as many things as fast but is exceptionally portable and easy to take with just about anywhere. It is incredibly light and portable and performed better in direct sun solar testing than any other smaller portable solar panel we tested.
We also tested quite a few battery banks with an integrated solar panel. Most of these options cost much less than solar panels without an integrated battery bank. However, these items don't work nearly as well — several of them failed to generate a measurable charge during our 1-hour test. To get them to convert sunlight into energy, we had to have them perfectly angled into the sun and wait three times as long to get even the smallest measurable amount of charge. So while these options are less expensive and come with an integrated battery, they aren't as good of a value when it comes to harnessing energy from the sun.
The BigBlue SolarPowa is one of the best values for a portable solar panel we tested.
Credit: Sam Schild
The main use for a portable solar charger is to power your device when you're away from power outlets. We took this into account when we weighted direct solar charging speed in our testing metrics. The main function of a solar charger is to charge electronics efficiently. With that in mind, it's no surprise that some of our highest-scoring panels in this metric were chargers with the largest capacity.
We used a set of 12 identical 10,000 mAh battery banks to execute this experiment. We hooked up each panel to one of these battery banks and then set them in the sun for one hour. We then measured the amount of charge each panel created in milliamp hours using a digital multimeter. We performed this test three times on every panel and averaged the results.
The BigBlue SolarPowa 28 generated the most power in one hour of direct sunlight, an average of 1849 mAh in an hour. This 28-watt panel put out consistent power and even outperformed a few higher-watt panels we tested. The X-Dragon 20W also performed admirably in direct solar testing, generating an average of 1043 mAh in an hour.
We tested all panels in side-by-side testing using identical battery banks in identical contitions.
Credit: Sam Schild
We tested a few solar chargers that have DC power output, and these panels performed the best when hooked up to the DC power stations we used in our 100+ watt solar panels test. The FlexSolar 40W performed better when using its DC charging output, generating 1466 mAh in an hour compared to 338 mAh in an hour when using the USB-A port hooked up to the 10,000 mAh test battery.
The SolarPowa 28 performed the best in our direct solar charging test despite not being the largest-capacity model in our lineup.
Credit: Sam Schild
The Goal Zero Nomad 50 generated an average of 1389 mAh over three tests, though it didn't perform noticeably better when hooked up to a larger battery with its DC charging output. The Goal Zero Nomad 20 also has a DC charging output, so it's capable of charging DC power stations as well, but this 20-watt panel only put out an average of 471 mAh in an hour and also didn't perform noticeably better when using the DC output.
The FlexSolar 40W solar panel has a DC charging output, and it put out more power from this output than the USB-A output we used for our main test.
Credit: Sam Schild
During direct solar charging testing, we found that four of the portable battery banks with an integrated solar panel weren't nearly as efficient as the others we tested — the Blavor Qi 10,000mAh, the Mregb 42800mAh, the Riapow 26800mAh, and the Errbbic 20000mAh. This isn't to say that these panels don't work at all, but that their conversion efficiency is incredibly low and slow. Not one of the integrated battery banks with a solar panel worked as well as the larger panels we tested. Additionally, we repeatedly had issues with these batteries overheating when placed on the ground in direct sun.
We found these panels really worked best only if you angled them directly at the sun. Even then, they're far less efficient than even the other 5-watt panels with slightly larger surface areas. We consider these panels as battery banks, first and foremost. The integrated solar panels on these shouldn't be relied on like you would any of the panels we tested here.
The Goal Zero Nomad 50 performed well in direct solar charging and it has a DC output so it can charge larger power stations.
Credit: Sam Schild
We devised a separate test for these four portable solar chargers, as well as the low-wattage BioLite SolarPanel 5+ — all of the models in our tests that have integrated battery banks. We left each of these panels to charge in the sun for three hours, hanging so they wouldn't overheat.
None of the panels generated nearly as much power as the larger models, but they did generate some charge eventually. In three hours, the Mregb 42800mAh created 339 mAh, the Blavor Qi 10,000mAh generated 235 mAh, the Riapow 26800mAh generated 134 mAh, and the Errbbic 20000mAh created just 42 mAh of charge. All four of these failed to generate any measurable charge during our regular testing, and we'd encourage people to think of them more as portable chargers than as highly functional solar panels.
The BioLite is the only one that generated any measurable charge during our regular test, pulling 135 mAh, and over the course of three hours, it managed to generate 443 mAh. This makes it the most efficient solar charger with an integrated battery bank. It has a much smaller battery capacity (just 3,200 mAh) and looks a lot more like a solar panel than the four brick-style battery bank "solar panel" combos we tested. The Biolite 5+'s solar panel worked comparably as well as the other 5-watt solar panel we tested, the Goal Zero Nomad 5, but was less efficient overall. While the Biolite 5+ generated 135 mAh of charge in one hour, the Nomad 5 generated 318 mAh.
Testing the Errbbic 20000mAh while hiking in Colorado: this panel and all the integrated battery bank/solar panel combos should be thought of as battery banks first, with a solar panel for emergencies.
Credit: Sam Schild
In this metric, we consider the following questions: is your panel going to quit on you just because one cloud passes overhead? To test this, we performed the same test we used to test direct solar charging with a white sheet suspended over all the panels to simulate a cloudy day.
Again, the highest-performing models in indirect solar charging speed were the ones with a larger watt rating. However, their performances do not directly correlate to overall wattage, with notable diversions where smaller panels converted more electricity.
The BigBlue SolarPowa 28 performed best in indirect solar charging testing, generating 919 mAh in an hour. This is a better conversion rate than the three larger 40 and 50-watt panels we tested. Compared to other similarly-rated panels in the 20-25 watt range, the SolarPowa once again blew the competition out of the water. When it comes to collecting dispersed rays through the clouds, this panel could not be beaten.
Testing solar panels in indirect light to simulate a cloudy day.
Credit: Sam Schild
Unsurprisingly, the solar chargers with large surface areas did better in this metric because there are more cells exposed to the sun at one time. The Goal Zero Nomad 50 did well in indirect solar testing, generating 616 mAh of charge in an hour. This panel is massive, so it stands to reason that it would do at least okay in less-than-ideal conditions where every bit of solar power is needed.
The X-Dragon 20W generated 535 mAh in one hour, which is quite impressive for a 20-watt panel. Compared to the other panels we tested of similar wattage (in the 20-25 watt range), this performance is several times larger than the competition. It even performed better than the FlexSolar 40W, a panel rated as twice its capacity, generating over 2.5x as much energy during this test.
The SunJack 25W didn't perform as well in the shade as some of the other panels we tested, but it still generated some power.
Credit: Sam Schild
The Goal Zero Nomad 20 proved to have less of a decrease in power generation from direct to indirect light than almost any other panel we tested. Though its output isn't quite as impressive as other 20-watt panels we tested, this increased consistency across weather conditions is notable and appreciated. And though it wasn't the most impressive panel of its watt size, it performed better than the SunJack 25W by generating 319 mAh in one hour compared to the 105 mAh of the SunJack 25W.
Disappointingly, if perhaps not surprisingly, all four of the battery-bank-with-solar-panel combo units — the Blavor Qi 10,000mAh, Mregb 42800mAh, Riapow 26800mAh, and Errbbic 20000mAh — failed to generate any charge at all during our indirect sunlight tests. This solidifies them, once again, as portable battery banks, first and foremost, with unreliable solar charger performance.
The Goal Zero Nomad 20 performed relatively better in indirect solar charging than it did in direct solar charging testing.
Credit: Sam Schild
We looked at each model's portability in terms of packed size and weight. Some panels fold down into a small package but aren't very light. Some other panels are lightweight but don't fold at all.
We considered how easy each portable solar charger is to set up and take down. We considered if they have storage solutions for your cables or features that make them easier to pack into a backpack or bring along on a camping trip.
The lightest models we tested were some of the battery banks with integrated solar panels we tested. The Blavor Qi and Errbbic 20000mA each weigh significantly less than any other model we tested, 9.3 and 8.7 ounces, respectively.
We weighed and measured every panel, and of course we carried every solar panel with us to asses how portable they are.
Credit: Sam Schild
Both of these battery banks with integrated solar easily fit into a pocket or clip to the outside of your backpack. But as we discussed earlier, these should be considered battery banks more than solar panels. The solar panels on all the brick-style battery banks really aren't big enough to rely on for solar power generation. While their low weights make them portable in this lineup, there are other portable chargers we've tested without solar panels that are lighter.
The Errbbic 20000mAh Waterproof is the lightest and most portable model we tested, but you shouldn't rely on it to generate enough power to recharge much.
Credit: Sam Schild
The Goal Zero Nomad 5 stands out for its portability among the rest of the lot of solar panels. This panel weighs a mere 12.4 ounces and is incredibly thin. It easily slides into any backpack, no matter how full it is. It easily straps to the outside of your pack if you want to get some charge while on the move. This panel doesn't fold, and it could be smaller if it did, but then it would have more heavy material and less total area for the actual solar panel. This panel strikes the perfect balance between ultralight weight consciousness and solar efficiency.
The Goal Zero Nomad 5 doesn't fold but is thin and small enough to strap on top of your pack while backpacking, making it pleasantly portable.
Credit: Sam Schild
The BioLite SolarPanel 5+ is another highly portable option. It weighs 13.4 ounces and is about the same size as the Goal Zero Nomad 5. The BioLite 5+ also has an integrated 3200 mAh battery, which makes its low weight and small size even more impressive.
The BioLite SolarPanel 5+ is another one of the most portable solar panels we tested and has an integrated 3200 mAh battery.
Credit: Sam Schild
The BigBlue SolarPowa 28 is the most portable panel we tested that's larger than 20 watts. This panel folds down to about the size of a notebook and weighs 20.9 ounces. It's more than light enough to throw in a backpack or on your bike to charge your devices anywhere. Compared to the Goal Zero Nomad 5, it weighs almost twice as much but packs serious charging power. On the other hand, compared to the beefy Goal Zero Nomad 50, which weighs 110.4 ounces, the SolarPowa 28 feels practically featherweight.
The SolarPowa 28 is one of the most portable 20+ watt panels we tested.
Credit: Sam Schild
The X-Dragon 20W is almost as light as the BigBlue SolarPowa 28 and about the same size when folded, too. The X-Dragon also has a large storage pocket, which makes it slightly easier to stay organized when you're transporting your solar charger. It has a large zippered pouch for storing cables and a battery bank protected by an extra flap of canvas. The canvas flap secures over the mesh pouch with velcro.
The X-Dragon 20W has a large zippered pouch that's protected by an extra flap of canvas.
Credit: Sam Schild
The FlexSolar 40W isn't the lightest panel at 47.3 ounces, but it does fold down very quickly and easily, making it notable despite its size. It's the easiest to pack away of any folding panel we tested, so it is more portable than its weight may make it seem. Once folded, it becomes a compact package. However, it lacks cable storage or charging port protection, which we don't love.
The FlexSolar 40W features six panels that fold down into a surprisingly small package.
Credit: Sam Schild
The SunJack 25W also folds and unfolds quickly, much like the FlexSolar 40W. But the SunJack only weighs 29.4 ounces, which is much lighter than the FlexSolar. This isn't quite as light as the BigBlue SolarPowa 28 or X-Dragon 20W, but it's more than light enough to carry around. We also appreciate that it has an excellent zippered compartment to store cables and a battery bank, which makes it that much easier to stay organized.
The SunJack 20W is one of the lighter panels we tested and has three panels that fold down quickly and easily.
Credit: Sam Schild
Some solar panels are easier to use than others. We evaluated many aspects of functionality in our testing of portable solar chargers. We looked at the number of devices each panel can charge simultaneously, integrated battery capacity, other charging options, and anything else that makes these panels more user-friendly.
As you might guess, when tasked with the challenge of charging multiple devices at once, the more powerful models performed better than lower-wattage models. Smaller panels, such as the 5W models, don't have the power to sustain two gadgets at once. If this is a priority for you, then select a panel with a higher wattage.
The BigBlue SolarPowa 28, SunJack, Goal Zero Nomad 50, and FlexSolar 40W all did a good job charging multiple devices at once. After so many rounds of testing these portable solar chargers' ability to juice multiple devices at a time, for the most consistent results, we recommend not doing this. Instead, it's generally more effective and efficient to use your solar panel to charge a battery bank and then charge all your devices off of that battery.
The SolarPowa 28 has three USB outputs to charge multiple devices at the same time and a velcro pocket to store cables and more.
Credit: sam schilc
Solar chargers with built-in battery packs excel in charging multiple devices at once, but we really consider these just battery banks, so that's to be expected. The Blavor Qi and Riapow are capable of charging compatible smartphones wirelessly as well. This is a useful feature, as it allows you to leave your cables at home, further cutting weight and system complexity.
The Blavor Qi 10,000mAh has a USB-A and USB-C output and is also capable of charging smartphones wirelessly.
Credit: Sam Schild
Beyond multiple device charging, several of the panels we tested have multiple types of outputs, which help to charge a variety of devices. The Goal Zero Nomad 50, Goal Zero Nomad 20, and the FlexSolar 40W have USB-A outputs and DC outputs, so you can charge more types of battery banks, including portable power stations. You can also connect multiple Nomad solar panels together to increase power output. You can even mix and match many of the Nomad sizes and models (though not the small, Nomad 5) to create larger stations pulling more power from the sun.
The Goal Zero Nomad 50 USB and DC outputs and is chainable with other solar panels, so you can double your power.
Credit: Sam Schild
All of the Goal Zero Nomad panels have kickstand legs that make it easy to angle them directly at the sun. This greatly improves solar efficiency when the sun isn't directly overhead, so you can maximize sunlight in the morning and evenings and during non-summer months.
The Nomad 5 has a single kickstand leg that lets you angle it directly at the sun to pull more power at harsher angles.
Credit: Sam Schild
The BioLite SolarPanel 5+ also has a kickstand leg to angle it at the sun. Uniquely, this model has a sundial to help take the guesswork out of pointing the panel directly at the sun. The integrated battery on the Biolite makes it possible to keep a small charge for when the sun goes down, but its limited capacity isn't enough to fully charge most modern smartphones. However, in an odd twist (in our opinion), there is no way to bypass the battery bank. So if the battery doesn't have a charge, you'll have to wait for it to charge before you're able to charge your device.
The BioLite SolarPanel 5+ has a kickstand leg and an integrated sundial to help angle the panel at the sun when it's lower in the sky.
Credit: Sam Schild
Deciding on the right portable solar charger can be an overwhelming task. We hope that our breakdown of these mobile models has helped you to narrow down which is the right choice for your devices, your weather, and your budget.
Authors Note: This has been updated on Feb 9, 2022 with updated information, links, and resources.
Table of contents:
What to know about using 6 volt batteries in your solar installation
If you live in an RV, van, or cabin, solar with battery storage is a great way to meet your energy needs. Once you’ve selected your solar panel kit, you’ll need to purchase a battery to store that energy produced from your panels. But how do you make sure that battery gives you the power you need and how do you know that solar panel will charge that battery effectively? Let’s break it down.
What are deep cycle batteries?
Deep cycle batteries may look similar to the batteries used in your car, but they are actually very different. In contrast to car batteries which only provide short bursts of energy, deep cycle batteries are designed to provide sustained energy over a longer period of time. Deep cycle batteries can be discharged up to 80%, but most manufacturers recommend not discharging below 45%. Regularly going beyond that point will shorten the life of the battery.
How do you charge batteries with solar panels?
Using solar panels to charge a battery, you’ll still need a charge controller. The wiring diagram below can offer you an easy understanding.
how to charge a battery from solar panel
Can you charge solar batteries without charge controllers? The answer is necessary and obvious, solar panels with batteries need a charge regulator which will be responsible for maintaining the charge of the batteries and keeping them in good condition. Solar batteries store the energy that is collected from your solar panels. The higher your battery’s capacity, the more solar energy it can store. In order to use batteries as part of your solar installation, you need solar panels, a charge controller, and an inverter.
When using batteries for solar panels as part of a home solar system, you’re able to store the excess electricity your panels produce instead of sending that energy back into the grid. Electricity will be sent to the grid if your batteries are fully charged and your panels are still producing energy.
Your solar panels will first need to be connected to a charge controller which will help monitor how much energy is stored in the batteries to prevent overcharging. Charge controllers will also shut down a system if the batteries become too depleted. Before powering your appliances, your batteries will need to be connected to an inverter to convert the DC energy collected from solar panels and converted to AC energy.
In addition to solar panels, you can also charge your 12V battery through grid power and alternators. But the other two ways will not be as economical as solar panels which offer access to clean and free solar power.
Deep cycle batteries have a specific amp hour rating. This refers to the amount of current that is supplied from the battery over a certain period of time. If you have a 200ah battery, it can supply 20 continuous amps for 10 hours or 10 amps for over 20 hours.
How many amps does a 100 watt panel produce?
Calculate the current in amps by dividing power in watts by the voltage in volts. When a 12V solar panel is rated at 100W, that is an instantaneous voltage rating. So if all of the test conditions are met, when you measure the output, the voltage will be about 18 volts. Since watts equals volts times amps, amperage will be equal to 5.5 amps (100 watts divided by 18 volts) . So your panel will produce 5.5 amps per hour.
How many panels would I need to charge a 200ah battery?
If you have a 200ah battery, only 80% of that is usable due to depletion limitations, so you really only have 160 amp-hours of energy to draw on. If you learn that you typically can last two days with energy from that battery, that means you consume 80 amp hours a day.
Based on the earlier calculation, a 100 watt panel will produce an average of about 30 amp-hours per day (based on an average sunny day). This means you would need three 100 watt solar panels or one 300 watt panel to fully recharge your battery on the average day.
How long will it take to charge a battery?
Total charging time depends on the weather, as well as state and type of battery. If a battery is completely drained, a panel can typically charge the battery within five to eight hours.
The total charging time will vary depending on the state of a battery. If a battery is totally drained, a solar panel can energize the cells within five to eight hours. The position of the sun in the sky can impact a panel’s charging speed. When sunlight shines directly on a panel in the middle of summer, the charging speed will be faster. Charging cycles are slower on cloudy days.
How many solar panels does it take to charge a 100ah battery?
Again we use the same calculation dividing power in watts by the voltage in volts to find amps. Charging your battery at 12 volts and 20 amps will take five hours to charge a 100 amp hour battery. By multiplying 20 amps by 12 volts, 240 watts is how big of a panel you would need, so we’d recommend using a 300w solar panel or 3 100 watt solar panels.
What are the best conditions to charge a battery?
You’ll find that all of Renogy’s deep cycle batteries have a normal operating temperature, storage temperature, and operating charge temperature specifications listed. Most batteries have a normal operating temperature of 77°F plus or minus 5.4°F. Most batteries have an ideal operating temperature between 50°F and 85°F. Batteries typically lose about 10% of their capacity for every 15°F to 20°F below 80°F. Their internal chemistries slow down, resistance increases and capacity and charge acceptance drop. This reduced capacity is temporary.
Does it matter what kind of battery you use?
Yes! Different batteries can have a huge impact on how your solar installation operates. There are three main types of deep cycle batteries used in solar systems: flooded lead acid, sealed lead acid, and lithium iron phosphate batteries. Each of these batteries vary in price, battery capacity, voltage, and cycle life.
For example, battery capacity is important because it measures the amount of energy you can store. If you need to power certain appliances for long periods of time, you'll need more batteries to carry a bigger load. Capacity is measured in total amp hours. Look at cycle life to learn about the number of discharge and charge cycles a battery can provide before the capacity drops below the rated capacity. This varies sharply from technology to technology and is measured in a number of cycles. For more information about battery types and how to choose the best battery for your system, refer to our blog post.
Do lithium batteries charge faster than flooded lead acid batteries?
Lithium iron phosphate batteries are more efficient than sealed and flooded lead acid batteries. They also have a faster rate of charge. This is because they can typically handle a higher amperage, which means they can be recharged much faster than flooded lead acid batteries. Lead-acid batteries are limited in how much charge current they can handle, mainly because they will overheat if you charge them too quickly. In addition, the charge rate gets significantly slower as you approach full capacity.
How do I size my battery bank and why is it important?
It’s very important to properly size your deep cycle battery bank. The amount of battery storage you need is based on your energy usage. Energy usage is measured in kilowatt hours. For example, if you need 500 watts for 8 hours per day, then your energy usage is 4kWh per day. A battery capacity of 4 to 8 kWh is usually sufficient for an average four-person home. Your energy needs may greatly differ from that depending on what you’re powering in your household.
What size battery do I need?
As the average power consumption for the US households ranges between 3kWh to 6kWh, you can find the suitable size and number of batteries in the table below.
To size a system that will best fit your needs, we recommend making a list of all the devices you plan on running. Get the wattage information, or the amps and volts of the product, and provide an average run time per device. The Renogy solar power calculator is a great tool that makes it a quick and easy process to help determine your specific needs.
Batteries usually come with voltage range on their product package or somewhere on their selling page. For example, a Renogy 12V 200Ah Lithium Iron Phosphate Battery has a nominal voltage of 12.8V, and its voltage range is 10 to 14.8V. When the battery is fully charged, the voltage will read a little higher than 12.8V, which means the voltage value of 12.8 to 14.8 can indicate the battery has been topped off.
Battery Capacity
Sizing your solar panels to charge a 12v battery depends on several factors. You must consider your battery capacity and your expected discharge rate before sizing your solar panels to suit your needs. After you’ve determined these two factors, you can determine what size solar panel will be sufficient to charge your 12v battery.
Your 12v battery capacity should be listed on your battery’s specification sheets or printed on the outside of your unit. Typically, capacity is listed in amp-hours (Ah).
A battery that has a 100Ah capacity will be able to provide 100 amps of power for one hour or 10 amps for 10 hours. If you have multiple batteries working together in a system, you may need to do some calculations to determine your battery bank’s total capacity and voltage.
If you have multiple battery banks wired together in parallel, you simply add the Ah ratings together to determine your total capacity and keep the voltage the same. For example, if you have three 100Ah 12v batteries wired in parallel, you would have a total battery bank capacity of 300Ah at 12 volts.
If your batteries are wired together in series, you are instead adding the voltages of the battery together while capacity remains the same. In the same example, with three 100Ah 12v batteries, if they are wired together in parallel, you would have a battery bank with 100Ah capacity at 36 volts.
Expected Discharge Rate
Calculating your discharge rate is important if you intend to continue using your batteries while they are charging.
If you have appliances that run around the clock — such as a refrigerator, air conditioner, or lights — determining their expected power draw will help you to ensure that your solar panels are powerful enough to both keep your appliances operating and charge your battery banks.
Power draw is typically expressed in watts, just like solar panel production capacity. It may be easier to understand how your battery capacity can handle power draw by converting amp-hours to watt-hours.
Using a 300Ah 12v battery system as an example, multiply the amp hours by the voltage to determine your capacity in watt-hours; in this case, 3600 watt-hours (Wh). A battery bank of this size can operate an appliance that consumes 300 watts for approximately 12 hours.
Determining the draw of your appliances can be done similarly. Most appliances will give you some indication of their expected power consumption.
Look at the charging cord, the bottom or back of your appliance, or the charging block — it should indicate either wattage or show you a voltage and amperage rating. If given the latter, convert it into watts by multiplying the voltage and amperage together. For example, a 120-volt appliance that draws 3 amps will use 360 watts.
Once you have your appliances’ power consumption ratings, you can determine your expected draw in a few steps.
Now that we have our expected discharge rate of 2780Wh, we can determine the size needed for our solar panels.
Sizing Your Solar Panels
Continuing with our example of a 300Ah 12v battery (with a 3600Wh capacity) and an expected daily discharge of 2780Wh, we can determine what size solar panels we need to both keep our appliances operating and fully charge our battery banks.
To operate these devices alone, you will need 2780Wh of power. Ideally, your solar panels will provide more than enough power to the system than needed to meet your daily needs alone, allowing your batteries to charge to maximum capacity for overnight use or periods in the shade.
If you add your total battery capacity to your expected daily usage for a total of 6380Wh, you can fully charge your 12v batteries from empty while simultaneously running all of your appliances.
Working with the 6380Wh estimate, we can calculate the power required from the solar panels. Solar panels are sold by watt, so this calculation is relatively straightforward, but there are certain components to keep in mind.
The main consideration is that solar panels don’t always operate at their peak efficiency, so estimating a 70% power production from each panel will give you a more accurate representation of their power production in typical use.
To reach 6380Wh in a typical 12 hour day, we follow a simple calculation: 6380Wh (desired energy production) / 12 hours (average hours of daily sunlight) = 531.67 Watts. In this example, we need the solar panels to produce 532 watts per hour for 12 hours to meet our energy goals.
Using our 70% power production estimate from earlier, we can further calculate: 531.67 Watts / 0.7 = 759.52 watts. This calculation brings us to the size of the solar power system we would need to appropriately power our 12v battery system while including daily consumption.
Combining Solar Panels for 12-Volt Battery Systems
If there isn’t a single solar panel that meets your energy needs, you can combine multiple panels to reach the desired wattage. For our above example, you could combine four 200 watt solar panels into an 800-watt system to exceed the desired output of 759.52 watts, or you could combine two 400 watt panels.
When connecting solar panels in parallel or series, you need to consider what the total output voltage and amperage are so that you can select an appropriate solar charge controller.
If connecting solar panels in series, the total system voltage is the sum of each individual panel’s voltage, while the amperage remains the same. In parallel, the total amperage is the sum of each panel’s, while voltage remains the same.
Conclusion
It can be intimidating when you first start navigating the solar and battery options out there. From deciphering amp hours from volts, sealed lead acid from flooded lead acid, there’s definitely a lot to consider. But by doing some simple math, properly calculating your energy needs, and learning a bit about the different battery options available to you, you’ll be well on your way to a battery bank to fit you and your household’s needs.
Now it's time to select your own solar storage system. Whether you want a 12v lithium battery, 12 volt deep cycle battery, 24v battery, 48v battery, or other type of batteries, you can find a suitable one at Renogy store!
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