How Long Does It Take a Solar Charger to Charge a Cell Phone?
Cell Phones are becoming increasingly essential for daily living.
In off-grid living, they help in keeping communication with friends, family, colleagues, and the likes.
For this reason, a solar charger is important to charge a cell phone outdoors.
Smartphones are very portable, making them easy to use outdoors.
However, the main problem is their duration of charge with solar chargers.
A solar charger will charge a typical cell phone in 2.5-3 hours from a 5W solar panel, 1.3-1.6 hours from a 10W panel, 52 minutes to 1.1 hours from a 15W panel, and 39-50 minutes from a 20W panel. These stats are based on a solar charger utilizing 80-100% of its listed power output.
Both the wattage of your solar charger as well as the battery size of your smartphone come into play when estimating recharging times.
The average charge times for various popular smartphones can be seen below. BigBlue 28W solar charger (portable solar panel)
Goal Zero Venture 35 Solar Kit with Nomad 10 (portable solar panel with battery bank)
Hiluckey Solar Charger (power bank with embedded solar panel)
- Portable solar panel with USB ports – Plug in your phone directly into the panel
- Portable solar panel with a battery bank – Either plug your phone directly into the panel or use the battery bank to charge from solar first before using the battery bank to charge your phone
- Power bank with embedded solar panel – Solar panel is sealed to the battery bank
Most solar power banks with embedded solar panels have a good size battery but lack solar panel output power.
The best “solar charger” for recharging your cell phone is a portable solar panel of 10W or more along with a battery bank.
Using the solar panel to recharge the battery bank will be the best way to recharge your cell phone from solar because solar power is inconsistent due to weather changes.
This could affect the way the panel charges your phone if you connect them together without the use of a power bank.
For example, I used my Nomad 10 solar panel to directly charge my iPhone 7 and it worked successfully, however, any Cloud cover would stop the charging and my phone would go back and forth from charging to not charging.
Charging a power bank would simply allow a faster charging process because it will provide consistent power to recharge your phone – as opposed to your phone constantly going in and out of sleep mode to show it’s charging.
If you’d like more information on power banks with embedded solar panels, I created a list of the top models and go into more detail on them in my article here: Top 7 Solar Panel Battery Banks – A Battle for Power.
Top 3 Solar Phone Charger Examples
The following examples will be portable solar panel models that can be used to charge your phone directly or indirectly via an optional battery bank.
In several cases, you can buy these in a kit along with a battery bank, like the Goal Zero Venture 35 with Nomad 10 kit (affiliate link).
BigBlue 28W USB Solar Charger
The BigBlue 28W USB solar charger is one of the most suitable chargers for cell phones. It possesses four different foldable SunPower solar panels that are very compact.
Also, it has three 5V/2.4A (max) USB output ports for simultaneous device charging.
However, the panel is best used with a maximum of two USB ports simultaneously to get the full 5V/2.4A for both ports.
This means that the USB ports combine for a maximum of 24W of output (5V/4.8A), which is not 28W but is still a relatively high number for a portable solar charger.
According to reviews, the BigBlue 28W USB solar charger appears to deliver a good output in sunny and, surprisingly, cloudy conditions.
On the downside, the BigBlue is a long solar panel when unfolded (33 x 11 x 0.2 in). Hence, users need to remain conscious of their size when using it for backpacking needs.
Nekteck 21W Solar Charger
The Nekteck 21W solar phone charger has three solar panels and two standard USB-A ports.
Each port is capable of 5V/2.0A when one port is used, but when using both ports, the maximum amperage is 3.0A (15W max).
Like the BigBlue, the Nekteck outputs less power than the panel says in its listing. That being said, 15W is enough to power up a smartphone or multiple phones when needed.
Although it has less power than the BigBlue panel, it’s more compact with an unfolded length of 26.2 inches.
This may be easier for you to mount onto your backpack or tent as it is about seven inches shorter than the BigBlue.
Impressively, it is also a lightweight solar charger, weighing only 18 ounces in total.
Goal Zero Nomad 10 Solar Charger
The Nomad 10 is an impressive product from Goal Zero.
It comes with a foldable solar panel, which has a wide surface area.
It weighs 1.2 pounds, which makes it relatively heavy, but compact.
The 10W, 6-7V panel comes with a built-in USB-A port, which functions effectively.
I’ve used this panel to successfully charge my phone directly, but the best option is to use one of Goal Zero’s battery banks for charging up.
The Flip 12 or Venture 35 are some options that are smaller for portability.
The two downsides to this panel are its decreased power output compared to the previous two panels as well as its cost.
The Nomad 10 by itself costs almost double that of the BigBlue or Nekteck panels.
But its compact size makes it useable for almost any purpose (9.5 x 14.5 x 0.75 inches unfolded).
You can see how the Nomad 10 worked in my own testing to charge my Sherpa power bank in my video below.
You can speed up your solar charger by angling it perpendicular to the sun and charging one device at a time. A direct angle to the sun allows the charger to absorb as much sunlight as possible. Charging one device at a time avoids splitting the charger’s output power between multiple devices.
If the device is placed outside your backpack while moving, please note that it may not charge fast.
Since you are on the move, there’s a high probability that the panels aren’t always facing the sun resulting in inconsistent charging.
If you want a faster charge from the solar phone charger, you may also consider using shorter cables.
Please note that shorter cables don’t necessarily make the solar phone charger work faster. However, it helps in the overall charging speed due to a minimal amount of wasted energy.
It may also be advisable to purchase a solar charger with a battery to help store power, which allows the user to charge at a time of convenience.
Do Solar Phone Chargers Really Work?
Solar phone chargers really work as long as they’re exposed to quality sunlight. It’s essential to pick a solar charger with at least 10 watts of power. A 10W solar charger will recharge a typical cell phone in 1.3-1.6 hours. Any charger less than 10W may output too slow of a charge to your phone.
Solar phone chargers that are closer to 15 watts or higher can charge a mobile phone along with other devices simultaneously.
The portability of your solar phone charger matters a lot.
Hence, it is important to confirm the weight and dimensions (folded and unfolded) of any panel you intend to purchase.
If your solar phone charger has large folded solar panels, it may be too heavy to carry.
However, large folded solar panels may have higher efficiencies (charge devices faster) due to a wide surface area.
For example, my Elecaenta 120W solar panel is massive and weighs almost 12 pounds! But this is clearly too powerful of a panel for simply charging a phone in most scenarios.
Some solar phone chargers don’t function well compared to others, depending on their output.
Ensure that you pick a brand of solar charger that works efficiently and that has good and honest reviews.
If you ever come across issues with your solar charger, I have a guide to troubleshooting your panel to get it working again. I also have some maintenance tips to prevent you from running into any issues while using it off the grid.
Is There a Difference Between Rechargeable and Solar Batteries?
There is no difference between rechargeable and solar batteries. Solar batteries are used in storing chemical energy, which gets converted to electrical energy. Solar panels trap energy from the sun, and it gets stored in batteries for later use. Hence, solar batteries are rechargeable batteries.
In some cases, solar chargers don’t come with rechargeable batteries (or any battery at all), which is usually a challenge.
A significant example of a product that doesn’t come with a battery is the Nekteck 21W solar charger. Users will need to buy a separate battery pack to make it a power bank as well.
Rechargeable batteries are electrical batteries that can be discharged and charged multiple times. However, they are produced in different shapes, sizes, and specifications.
There are lots of different combinations of electrolytes and electrode materials utilized. Examples are nickel-cadmium (Ni-Cd), lithium-ion (Li-Ion), nickel-metal hydride (Ni-MH), lithium-ion polymer (Li-Ion polymer), and lead-acid.
Li-ion batteries are very stable batteries with a low self-discharge rate but high energy density and voltage capacity. Besides, they are very durable batteries.
Li-ion batteries tend to last for eight or more years and have nearly zero memory effect. So, even if the are a little high, it is worth the investment.
Introduction: How to Make a Solar IPod/iPhone Charger.aka MightyMintyBoost
About: I’m a former bicycle industry designer turned professional jeweler. I like working with my hands and am happiest when I’m in the shop building my creations. If you need help with your project just let me know! About Honus »
I wanted a charger for my iPodTouch and the MintyBoost was definitely my first choice. I wanted to take it a bit further and make it not only rechargeable but also solar powered. The other issue is that the iPhone and iPodTouch have large batteries in them and will deplete the two AA batteries in the MintyBoost rather quickly so I wanted to increase the battery power as well. What I really wanted was a MightyMintyBoost!
Apple has sold over 30 million iPodTouch/iPhone units- imagine charging all of them via solar power. If every iPhone/iPodTouch sold was fully charged every day (averaging the battery capacity) via solar power instead of fossil fuel power we would save approximately 50.644gWh of energy, roughly equivalent to 75,965,625 lbs. of CO2 in the atmosphere per year. Granted that’s a best case scenario (assuming you can get enough sunlight per day and approximately 1.5 lbs. CO2 produced per kWh used.) Of course, that doesn’t even figure in all the other iPods, cell phones, PDAs, microcontrollers (I use it to power my Arduino projects) and other USB devices that can be powered by this charger- one little solar cell charger may not seem like it can make a difference but add all those millions of devices together and that’s a lot of energy!
There are some really nice features about this charger:
It’s solar powered! It’s small. Large battery capacity- 3.7v @2000mAh On board charger charges via solar, USB or wall wart. Accepts input power from 3.7v to 7v. Remove the solar cell after charging and you have a nice compact USB power supply. Unplug the solar cell and use the Velcro to secure the MightyMintyBoost inside a backpack or messenger bag- now plug in a larger solar cell attached to your bag for even faster charging. Using a slightly larger solar cell (6v/250mAh) you can generate enough power to fully charge an iPhone in about 5.5 hours and an iPod Touch in 4 hours.
Building this is really easy and straightforward- it only took me around an hour so follow along and build one for yourself!
Safety note and general disclaimer: Be careful cutting the Altoids tin as it can have some really sharp edges- file them smooth if necessary. Assemble this at your own risk- while it is really easy to build, if you mess something up there is the potential to damage the electronic device you are trying to charge. Be careful in your assembly and soldering work and follow good safety practices. Only use a type of battery charger specifically designed for the type of battery you are using. Please read through the entire Instructable before asking questions- if there are are any questions just ask and I’ll help out as best as I can!
Step 1: Tools and Materials
Here’s what you’ll need to build your own MightyMintyBoost:
Tools: Soldering iron Scissors Wire cutters Pliers (or muiltitool) Multimeter Metal shears Clear packing tape
Materials:MintyBoost kit Lithium polymer battery charger (the original one specified was discontinued) For better performance use the Adafruit Solar Lithium charger (connections are similar but it’s slightly larger- see update below)3.7v 2000mAh Lithium Polymer batteryJST connector/wireSmall solar cell 2 x 3 adhesive backed Velcro Small double sided adhesive squares Altoids tin
7/10/10 UPDATE: Adafruit now also sells all the parts you need to make this a bit more mighty. Have a look here!http://www.adafruit.com/blog/2010/07/09/how-to-make-a-solar-mintyboost-a-solar-power-charger-for-your-gadgets/
7/18/11- ANOTHER UPDATE: Adafruit recently introduced a new LiPo charger that is specifically designed for solar charging that has much better performance. It’s not as small but the performance gains make it worth it. Have a look and read about the design here-https://www.adafruit.com/products/390
The single cell Lithium Polymer charger can accept input power that ranges from 3.7 to 7v maximum. When the cell reaches full charge the charger will automatically switch to trickle charging. When charging using the mini USB port, the charging current is limited to 100mA. When charging using the barrel plug jack, the charging current is limited to 280mA.
The solar cell maxes out at approximately 5v @ 100mA in bright sunlight. If you need faster charging simply use a larger solar cell- a 6v cell @ 250mA would work very well and they are easily obtainable and inexpensive. I used the size of solar cell that I did because I wanted it to be super compact.
I could not find out from the manufacturer if the solar cell I used has a blocking diode. A blocking diode is used in many solar charging systems to prevent the solar cell from draining the battery during low light conditions. Instructables member RBecho pointed out that the charging circuit used negates the need for a blocking diode in this application. You can tell when the solar cell is producing enough power because the little red LED on the charger will come on during charging.
Step 2: Build the Minty Boost Kit
First build the MIntyBoost kit according to its instructions. It’s really easy to assemble- even a complete novice can do it.
Instead of connecting the battery holder in the kit, we’re going to solder a JST connector to the MintyBoost PCB. This tiny connector will then allow the MintyBoost circuit to connect to the Lithium Polymer battery charger circuit. Make sure you get the polarity correct!
Test the MintyBoost by connecting the battery pack (make sure the battery pack has a charge) and charger circuit. The MintyBoost connects to the connector marked SYS on the charger board and the lithium polymer battery connects to the connector marked GND.
Now cut a notch in the Altoids tin for the USB port and use some double sided adhesive to mount the PCB to the Altoids tin.
Step 3: Add the Battery and Charger
Now cut a notch out of the other side of the Altoids tin to fit the charger and secure the charging circuit to the bottom of the Altoids tin with double sided adhesive. Reconnect the battery and the MintyBoost PCB to the charging circuit. Make sure nothing on the bottom of either one of the circuit boards is touching the bottom of the Altoids tin.
Step 4: Add the Solar Cell
There are a couple of different ways to connect the solar cell. The first is by simply shortening the connector leads and plugging the barrel plug into the barrel jack on the charging circuit.
The second method is to replace the connector with another JST connector and plug it into the third connector marked 5v on the charging circuit. I didn’t have another JST connector handy so I just soldered a salvaged two pronged connector to the charging circuit where there are two open pins on the 5v line.
Using the second method certainly is a bit cleaner since you don’t have the big barrel plug sticking out of the side of the tin.
UPDATE- Since the original charging circuit has been discontinued, the best way to connect the new version Sparkfun LiPo charger is to splice a mini USB cable to the solar cell wires so it can plug directly into the charger. There is a simple guide on how to do this here-http://ladyada.net/make/solarlipo/
Now attach the solar cell to the top of the Altoids tin using some 2 wide Velcro. I wrapped the battery pack with a layer of clear packing tape to help protect it. Then the battery pack is simple set down on top of the two circuit boards- it’s a near perfect fit.
Now set your MightyMintyBoost out in the bright sun and charge it up! You should see a little red LED on the charger board light up. Once it’s fully charged connect your iPod/iPhone/USB powered device and enjoy!
Step 5: FAQ and Additional Info
Here’s a list of frequently asked questions:
Q: Is it possible to overcharge the Lithium Polymer battery?A: No- the charger will automatically switch to trickle charging and then shut off.
Q: Is it possible to drain the Lithium Polymer battery completely and damage it?A: No- the battery has its own low voltage cut off circuitry that will prevent it from completely discharging- the low voltage cut off is around 2.8v
Q: Does the solar cell have a blocking diode to prevent it from draining the Lithium Polymer battery?A: No blocking diode is necessary- the Lithium Polymer charger prevents the battery from leaking current.
Q: How long will it take to fully charge the Lithium Polymer battery and how long will it take to charge my iPod/iPhone?A: How long it will take to fully charge depends on the amount of sunlight available but as a rough guesstimate it would take around 20hrs using the small solar cell in direct sunlight. Using a larger solar cell could easily take half if not one third the amount of time. Those same figures would apply if you were charging it over USB or using a wall wart power supply.
Charging your iPod is much faster. How fast it does it depends on your device’s battery capacity. An iPod Touch has a 1000mAh battery so it should fully charge it in around 2hrs. A 3G iPhone has a 1150mAh battery so it will take slightly longer and a 2G iPhone has a 1400mAh battery, so it will take around 3 hrs.
Q: The Lithium Polymer charger has an input voltage range of 3.7v minimum to 7v maximum- what if I want to use a higher output solar cell for faster charging?A: To use a solar cell with a voltage output greater than 7v, you need a voltage regulator to drop the voltage to a level that the charger can handle. You could use a 7805 voltage regulator to limit the output to 5v.they only cost about 1.50 and are very simple to wire up. The 7805 will give you as fixed 5v and is usually good up to 1A current. You could also use a LM317T which is an adjustable regulator, but it would involve a bit more circuitry to use. Some people also use diodes to drop voltage, since many diodes have a voltage drop of.7v
The other option would be to use a 6v/250mA solar panel. This will stay within the current input range and voltage input range of the Lithium Polymer charger. Remember that you can also connect smaller solar cells in parallel to increase the available current- two 5v/100mA solar cells connected together in parallel will give an output of 5v @200mA
Q: What if I want to use a charger with a higher input current limit?A: Sparkfun does have a Lithium Polymer charger that maxes out at 1A:http://www.sparkfun.com/commerce/product_info.php?products_id=8293
Q: How would I connect the more powerful charger- there doesn’t appear to be a clear way to do this?A: To use the more powerful 1A charger you would need to wire a two way switch to the battery so that in one position the battery would be connected to the charger and in the other position the battery would be connected to the MintyBoost circuit.
Q: Will this work with USB devices other than iPods and iPhones?A: You bet! There’s a list here: http://www.ladyada.net/make/mintyboost/
Q: Won’t the inside of the Altoids tin short out the circuit?A: No- using double sided foam tape to mount the circuit boards keeps the bottom of the board from coming into contact with the inside bottom of the tin. If you’re really worried you can cover the inside bottom of the tin with clear packing tape.
Q: How much does this cost? Can I build it for less? Is it cost effective?A: If you buy everything as listed it would cost 70.75 (not including the Altoids tin or shipping.) If you wanted to scratchbuild it using the MintyBoost PCB from Adafruit, building your own charging circuit and supplying your own parts from various sources you can save quite a bit. Both the charging circuit and the MintyBoost circuit are available online- just go to the web pages listed in the tools and materials section- they’re also listed at the bottom of this page.
Both Maxim and Linear Technology supply free samples (according to their websites) of their ICs so you just need to provide all the other bits (available from places like Mouser and Digikey.) Using a slightly smaller solar cell and a 2200mAh battery it is possible to build it for a lot less:
After adding up the small parts for the MintyBoost circuit, a small blank PCB for the charging circuit (you would have to etch the board yourself) and a mini USB connector, you could conceivably build this for around 21.00 (not including shipping or an Altoids tin.) It wouldn’t be exactly the same of course, but it would be functionally the same. I don’t know if the 2200mAh battery would fit into an Altoids tin either. It would be a LOT more work of course, and there could be a fair bit of troubleshooting if you’re not experienced in building these types of circuits or soldering surface mount components.
So is it cost effective? Absolutely- it just depends on the amount of work you want to do. Either way, you get a very useful and versatile solar powered charger.
Q: How did you calculate the power usage and equivalent CO2 values?A: Here’s the math-3.7v (LiPo rated voltage) x.1A (solar charge current)=.37W.37W x 12.5hrs (charge time based on average battery capacity) = 4.625Wh4.625Wh x 365 days = 1688.125Wh per year1688.125Wh per year x 30,000,000 units sold = 50,643,750,000Wh total used per year (50.644gWh)50.644gWh per year x 1.5 lbs CO2 produced per kWh used = 75,965,625 lbs. CO2 produced per year
Granted these are more or less maximum values but they clearly show some potential for some serious energy savings. A 12.5hr solar charge time per day isn’t realistic for the majority of the planet but if you shorten the solar charge time to approximately 4.5hrs at a 280mA current the results still remain the same.
The 5 Best Solar Powered Chargers for Your Phone or Tablet
We all know the sudden drama that happens during our outside pursuits when we see a “low battery” warning on our phone, tablet, digital camera or other device. Outdoors you’ll find yourself many times far from any power outlet to recharge your devices.
What will you do then? Have you ever considered carrying with you a solar powered cell phone charger?
Whether you’re on a camping trip, mountain biking, traveling the world or just walking around town a portable solar charger can help keep your devices powered up anywhere under the sun.
The idea of portable solar gear that uses free off-grid solar energy to power up our mobile lifestyle is pretty amazing. It’s surely one of the best inventions of this century.
Solar battery chargers come in many different shapes, sizes and efficiency ratings. We’ve done the hard work already and picked the top five solar powered chargers available right now for sale on Amazon that have the latest photovoltaic (PV) technology and the best charging performance.
We have also included a buyer’s guide at the end of the article where you’ll find everything you need to know about choosing the best solar charger, so make sure to check that out as well.
Best Overall: BigBlue 24W Solar Powered Charger
The BigBlue 3 USB ports 24 Watts solar charger is our top pick for the best solar phone battery charger to buy in 2022 because it offers a remarkable combination of manufacturing quality, price, portability, and charging speed.
It features highly efficient energy conversion SUNPOWER solar cells (up to 23 percent efficiency) and SmartIC technology, which means that this charger will automatically recognize the charging protocol of your devices so that it can deliver the most suitable and fastest charge possible. Three USB ports allow you to plug in and split the current between 3 devices at once.
What makes BigBlue the best portable solar charger for almost any kind of environment is also its charging performance in diverse weather conditions. This charger delivers a steady energy flow even on cloudy days so you can confidently plan your outdoor activities without having to worry about low battery devices.
The BigBlue solar panels delivers 24 Watts under direct sunlight and it charged our iPhone 11 from zero to full in about two hours. During cloudy days the charging capacity varies according to the Cloud exposure, but it should be able to charge anywhere from 20 percent and above which will be very useful especially in emergency situations.
This solar charger is made of four SunPower solar panels sewn into a durable canvas and a fifth section that’s more like a small pouch for storing your iPhone or Android phone while charging and thus protecting them from the direct sun exposure and overheating – however, if you have a cable long enough, it’s always better to move your devices into the shade. You can also easily store all the cables in this department.
Inside the pouch there are three USB ports that deliver up to 2.4A per port or 5V/4A overall (depending on how much direct sunlight hits the solar panels), and a small LED that indicates when there is power flowing from the panels.
What about portability? The BigBlue solar powered charger weighs 754 grams or 26.6 ounces and the entire solar charger folds up to about 14 millimeters or 0.55 inches thick. This makes it perfect to carry around when traveling, backpacking, going to work, or school.
To get the most out of your portable solar gear, we highly recommend pairing the BigBlue charger with a USB battery pack. For example, the Anker PowerCore Elite 20,000 mAh power bank is fully compatible with the BigBlue 24W solar charger and it can store enough energy to charge an iPhone 11 from zero to full six times. A portable battery pack like this one is a must-have since the solar chargers themselves cannot store energy and provide it during night time when the sun is not around. With a charged power bank, you are powered up 24/7.
What we like:
- Great value for the price
- The SmartIC technology
- Amazing charging speed
- Three USB ports
- High quality material
- Very compacted when folded
What we don’t like:
- Removable USB hub would make packing better
- A charging cable for iOS devices could be included
The Lightest and Most Flexible: Portable Solar Panel Sunslice Fusion Flex 12
Sunslice Fusion Flex 12 Watts with two USB ports (5V) each with max output of 2.4A is a perfect option for those who like to FOCUS on their outdoor experience without worrying about maintenance of the devices they bring along.
Two portable solar panels are extremely lightweight (just 270 grams/9.5 ounces) and easy to fold into a thin A4 like shape. That’s it, you can head out now! Then you just open the pack for solar cells to face the sun and use right away on the go by plugging in your USB devices like a smartphone and/or tablet. Additional plus are two elastic fasteners and two carabiners you receive with the product to easily attach the charger to your backpack.
The solar panel is made off CIGS thin film solar cells, which are a versatile option when it comes to application and practical use of photovoltaic technology. The thin film is flexible, you do not have to worry about bending the panels to fit better in your backpack. According to the manufacturer, the solar cells reach up to 16.5% efficiency in the perfect sunny conditions. Thin film solar cells perform better than crystalline solar cells when exposed to the strong summer sun, they maintain better power production when their surface heats up – this happens quickly on hot days. On the other hand, in colder weather, their performance drops compared to monocrystalline cells.
When it comes to performance under cloudy conditions or during the days when clouds come and go, you may need to carry a power bank with you rather than relying solely on this solar charger. The current drops pretty fast when shaded and takes couple minutes to restart once again. This means it may not provide enough power to charge your phone on cloudy days.
The manufacturer thought of the practical use for adventurers by designing the product with the protective and light transmitting EFTE coating – therefore, it doesn’t affect the efficiency of solar cells. The coating feels to the touch pretty much the same as a material of your backpack, yet it is scratch proof and has somewhat self-cleaning properties. Additional advantage is water resistance.
Sunslice Fusion Flex 12 is a practical and durable solution for spontaneous, short trips when you don’t know where and through which terrain your steps will lead you. On a sunny day, all you have to care about is your experience, meanwhile, this solar charger will be there to give you a bit of extra power to use your devices when they are running low of battery.
What we like:
- Scratchproof CIGS solar cells
- Great charging speed
- Easy to attach
What we don’t like:
Best for Price: Hiluckey 25,000 mAh Outdoor Portable Solar Power Bank
The Hiluckey 25,000 mAh had the best performance in the solar power bank category. If you’re looking for a solar power bank, look no further than this one.
It features 4 small solar panels that deliver in total 4.8W under direct sun. That’s the most wattage output you can get out of a solar power bank at this moment. While the solar panels on the BigBlue perform four to five times better than the Hiluckey, the PowerPort doesn’t have its own power storage. When there is no sun, there is no power flowing, so an additional external battery is needed to keep devices charged up when the sun is not around.
The Hiluckey Outdoor Power Bank on the other hand, has a built-in battery pack with a capacity of 25,000 mAh which can store enough energy to charge an iPhone 7 about three times and has two USB ports to charge your friend’s smartphone in the same time.
The built-in battery can be recharged by sunlight, but also by wall outlet. It comes with a built-in flashlight and four LEDs that indicate battery life. The casing is shock-proof, dust-proof and water resistant. Great for outdoors
The only drawback of this solar power bank is the charging speed from the small solar panels. In full sun, the Hiluckey built-in battery could reach just 15 percent battery after three hours. However, the charging speed from the built-in battery to our iPhone 7 was very similar to the BigBlue.
We recommend to always charge the power bank by wall outlet before heading outdoors. This way you’ll have enough power to recharge your devices several times, regardless of weather or time of the day. The solar panels on the Hiluckey are not designed as the primary source of charging, but they are a very good alternative to add extra power to the power bank anytime you’re under the sun.
What we like:
- Great value for the price
- High-capacity 25,000 mAh battery
- Overcharge protection
- Two USB ports
- High quality material
- Very compacted when folded
- 12-month warranty
What we don’t like:
Versatile Solar Phone Charger: Neckteck 21W
No matter what environment you’re dealing with, the Neckteck 21W is the Range Rover of solar power chargers. With an ultra-portable design, this solar charger with two USB ports is IPX4 waterproof, dust-proof and shock-resistant. The whole pack weights a little over 17 ounces (approx. 480 grams) and is super easy to use without any worries about your devices.
This charger features a solid construction and three monocrystalline solar panels based on innovative SunPower Maxeon technology that reach the maximum efficiency of up to 23 percent. The solar panels provide 2.0A per port or 3.0A max in total to charge your devices on the go. As other good quality solar chargers, it protects your devices from over current and overcharge, which could damage them if this feature were absent.
A great advantage of this handy solar charger is its compatibility with the most USB devices. It charges great variety of smartphones, which is not always the case with portable chargers. The package doesn’t come with cables. Do not forget to bring your own.
We would recommend it for charging your phone on a sunny day. An impressive feature unique to this solar charger is quite nice charging speed it provides when in the direct sun. In good sunny conditions it works flawlessly and can charge your phone as needed.
However, to get the best outcome when the weather is not perfect or when hiking through shady areas like in a forest, you should consider using this solar charger to charge a portable power bank and use the power bank to charge your phone later. The results are better this way, as the charge interruption recovery is on a slower side.
What we like:
- Great value for the price
- Monocrystalline solar cells
- Two USB ports
- High quality material
- Great for charging variety of smartphones, tablets power banks
What we don’t like:
Best Solar Panel to Charge a Power Station: Goal Zero Nomad 20
This amazing device boasts an impressive charging speed that performs very similar to the BigBlue Solar Charger.
Goal Zero Nomad 20W uses industry leading monocrystalline photovoltaic solar cells to offer a Rapid and steady charge during unobstructed sunny conditions and can bring a smartphone to full battery in less than two hours. This 20 watt solar charger is compatible with most small and medium devices, but can even charge a laptop in approximately 6.5 hours when under direct sunlight (the time is dependent upon the conditions).
The three solar panels are waterproof, UV protected, and scratch-resistant, offering you a durable and reliable portable power anywhere you go. The set comes even with a kickstand, allowing you to position the panels to reach their best potential when you need them to. Although the Goal Zero solar chargers are a bit on the pricier side, they do well when you need to charge smaller portable stations for storing extra power. It is compatible with a reliable Goal Zero 200x power station, which will safely charge your laptop, camera and other latest USB-C devices.
Weighing 2.26 pounds (1,000 grams), the Goal Zero Nomad is not as lightweight as other solar chargers we mentioned earlier, but it’s still a compact charger that can fit just about anywhere. When folded, it occupies pretty much the same space like a small laptop. Because of its reliability and power, this portable solar charger is frequently used by mountaineers in their expeditions.
What we like:
- Amazing charging speed
- Overcharge protection
- Compatible with laptops
- High quality material
- Very compacted when folded
- 12-month warranty
What we don’t like:
Most common uses of solar chargers
In the hectic world of today most of us cannot imagine our lives without gadgets. And the more advanced they get, the more power-hungry they become. That’s when a portable solar charger comes handy. Think of it like having your personal power supply, anywhere you go.
Complete freedom from power outlets!
Solar chargers are lightweight, foldable and easy to carry around. All you have to do is position the solar charger under the sun and it will immediately start recharging your devices. You can even strap it on your backpack and power up on the go. This way you can enjoy your daily activities without rushing to look for a power outlet somewhere inside.
Considering the fact that solar powered phone chargers are now so much more affordable and efficient, they can be a life-saver in many situations.
Solar energy brings light to our unsustainable developing world and by going solar, be it portable or not, is a great way to join the climate change battle by reducing your carbon footprint.
Important solar charger considerations
The most important features you should look for when choosing a portable solar charger are:
#1 Charge Interruption Recovery
Chances are you won’t be able to use your portable solar charger in full sun all the time. Especially if you live in a place like the United Kingdom. Areas with shade or clouds will affect the performance of your solar phone charger to a certain extent. We measured the output power of each model in full sun, and then in fairly cloudy conditions for one hour each in order to see which solar charger recovers the fastest and gets back on track after being shaded.
The best performing models in this category were the chargers with the most wattage power like the BigBlue. The Neckteck 21W scored the lowest in this test because of the small wattage power.
Larger solar chargers have more solar cells exposed to the sun simultaneously and this makes it easier to recover to maximum output after an interruption.
#2 Charging Speed
Most of the time, portable solar chargers are being used to charge devices such as smartphones, tablets, camera batteries, etc. when source of electricity is not available. This is the reason why we decided to test the charging speed of our solar chargers with an iPhone 7 and see how much it can charge from zero of full in direct sun.
To our surprise we found that the charging speed performance of our models was very different. This significant variability is clearly because of the wattage output power, but also due to type and quality of solar cells.
The winner in this category, the Goal Zero Nomad 20, outperformed the competition with an impressive charging speed.
Our advice: If you are looking for the fastest charging speed, choose a solar charger with at least 15 watts. While smaller panels are more lightweight, the charging speed of a 5W solar charger for example, is around three to four times slower than a 15 watts charger.
#3 Weight and Portability
The ideal portable solar charger would be light, small and easy to carry around. The most lightweight model in our competition is the Hiluckey 25,000 mAh Outdoor Portable Solar Power Bank, weighing just 11.8 oz. This is the only model to get a 10 out of 10 in this category.
However, keep in mind that small wattage chargers are less powerful, so if weight is not extremely important to you, we highly recommend choosing a charger with a higher wattage than the Hiluckey model.
Since they are used mainly outdoors, solar chargers are constantly exposed to the elements, so durability is a very important factor. All the models we tested had more or less the same quality of material and stitching and all panels were weatherproof.
Solar technology is advancing very fast and companies have already integrated the most advanced features found in residential solar systems into portable solar panels as well.
Watts, Amps, and Milliamp Hours (mAhs)
These are the three most common terms and features that are worth considering when when looking to buy a solar powered phone charger.
mAh – Milliamp hours is the easiest way to measure the strength or capacity of a power bank. This term is not used for the panels themselves, but just for batteries. The higher the mAh, the more power it can store and therefore the longer the power bank will last.
Amps – Amps on a solar charger will determine how fast the electric current flows in order to charge up your devices. The current drawn is different from device to device but in the case of portable solar chargers, you’ll get between one and three amps. The solar chargers we picked in our review test feature the highest amp power available on the market right now.
Watts – Watts are a measure of how much energy is being released to charge your devices. It’s the result of multiplying voltage by amps and they are the most frequently mentioned unit of power. Since USB ports operate at approximately 5 volts, a single 2 amp USB charger port (for comparison: a laptop usually has 1.5 amps in a single USB port) for example, would have a wattage rating of 10W (5 x 2) and therefore would require a 10W panel to charge at 2 amps. But in reality, a 10W solar charger won’t produce exactly 2 amps USB charge because of imperfect weather conditions (Cloud cover) and type of solar cells.
Types of portable solar panels
Solar chargers can either feature monocrystalline, polycrystalline or the super lightweight CIGS panels.
Monocrystalline PanelsMonocrystalline technology is the one that started the photovoltaic revolution and it’s still the most efficient even today when it comes to converting solar energy into electricity. As the name suggests, monocrystalline panels are made from a single crystal of pure silicon. They have an efficiency rating of up to 22 percent and can be easily recognized by their black uniform cells.
Polycrystalline PanelsUnlike monocrystalline panels, the polycrystalline modules are made up of multiple crystals but still deliver a great efficiency of up to 17 percent. Polycrystalline panels have a blue color and they usually cost less than monocrystalline panels.CIGS PanelsCIGS panels consist of Copper, Indium, Gallium, and Selenide solar cells. They are very different than mono- and polycrystalline panels. These panels are the most flexible and lightweight, but also the less efficient out of the three types in converting sunlight into usable power. It’s a good option for backpackers or trekkers who want to travel ultra-light. These are not as durable as the monocrystalline modules but they still do a pretty good job in case of emergency.
Do you need an external battery, or is a solar charger sufficient?
Portable solar chargers can recharge your devices – but only in direct sun. If you want to recharge your smartphone during night time, or on a rainy day, the solar panels will not be of any help.
On the other hand, a battery pack like the Anker PowerCore Elite 20,000 mAh, can store energy and provide continuous and steady power to recharge the same devices you would charge with solar chargers.
Thanks to modern technology battery packs nowadays are very light and can be recharged by solar panels or wall outlet and they can store a lot of energy, enough to recharge a smartphone up to seven times in one go.
Since battery packs can be charged from solar panels as well, adding one to your solar kit means you can have power for your electronic devices available at any time – even when the sun is not there.
How to get the most from your solar charger
Simplicity makes solar power truly remarkable. The only care and maintenance most solar chargers require is making sure they’re clean and dust free. A moist cloth should get the job done most of the time.
To get the highest charging efficiency, it’s important to position your solar panels correctly. A good rule of thumb is that the angle, relative to flat ground, must be approximately the same as your latitude, with a few small adjustments according to the seasons (shallower in the summer and steeper in the winter time).
The Best Solar Chargers of 2023
Cory Gunther / How-To Geek
Sydney Butler Writer
Sydney Butler has over 20 years of experience as a freelance PC technician and system builder. He’s worked for more than a decade in user education and spends his time explaining technology to professional, educational, and mainstream audiences. His interests include VR, PC, Mac, gaming, 3D printing, consumer electronics, the web, and privacy. He holds a Master of Arts degree in Research Psychology with a FOCUS on Cyberpsychology in particular. Read more.
Elizabeth Henges Commerce Editor Elizabeth Henges is the Commerce Editor for How-To Geek. She has close to a decade’s experience reporting on tech, gaming, and gadgets. Elizabeth has had her commerce work featured on XDA Developers, The Inventory, and more. She has also written for publications The Washington Post and The Verge. Read more. About How-To Geek
Whether you’re dealing with an unreliable power supply or want to make sure you can charge your essential gadgets when far away from the grid, a solar charger is an essential part of your hiking, travel, or emergency kit.
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24 Models Evaluated
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What to Look For In a Solar Charger in 2023
Before we get into what makes for a good solar charger, let’s clear up what we mean by “solar charger” since it’s distinct from concepts like a “solar power bank” or “solar panel.” A solar charger is a device that converts solar power using solar panels into an electric current suitable for charging devices, usually in the form of a USB power port conforming to USB power specifications. Solar chargers typically don’t have any power storage of their own, but you can use the charger with a power bank of your choice. In general, putting a lithium battery in direct sunlight is not a good idea, so it makes sense that most solar chargers don’t integrate them. Instead, you’d use a lengthy cable to connect devices under shade or in your bag, protected from direct sunlight. It’s important to use a solar charger with the necessary safety circuitry to prevent device damage. In models with poor safety controls, too much voltage may go to the device, damaging it. The charger may also keep pushing charge to the device even though it’s full. So look for mention of overcharge protection and other similar features. If you do use a charger that doesn’t explicitly mention these features, it’s usually a better idea to charge up an inexpensive power bank, rather than charge your tablet, phone, or other devices directly. Then use the power bank to charge your devices in turn. Size, weight, and mounting features are other key considerations. Small, foldable, and light solar chargers are more common now. Despite their size, they can produce usable amounts of power thanks to advancements in solar panel efficiency. Chargers may come with backpack mounts, kickstands, frames, or other mounting solutions. It’s best to pick one that matches your use case. For higher-capacity chargers, it’s always nice to have multiple ports to charge several devices simultaneously. Weatherproofing is a must since the odds of it raining at some point are virtually assured. Finally, an oft-overlooked feature is “auto resume.” Many solar chargers will stop charging when the sunlight drops below a certain level, and then fail to resume unless you manually reinsert the charging cable. Chargers with auto-resume ensure you don’t come back after a few hours to find that your device stopped charging ages ago.
Frequently Asked Questions
Solar chargers don’t store energy, and they need sunlight to produce electricity, so sadly, you can’t use them without sunlight.
Yes! Even if it’s cloudy or overcast, you’ll still get power from the sun. Things may not charge as quickly, but there’s still plenty of usable light.
In theory? Yes. In practice? Apart from the flashlight putting out a low total amount of power as light, it’s not in the same spectrum as sunlight, and it would be so inefficient that there’d be little point.
It all depends on the peak wattage of the charger in question and how much sunlight you’re getting. Under good conditions, it’s totally possible to get the same charge rate as typical wall chargers.
Best Solar Charger Overall: Anker 24W 3-Port USB PowerPort
Anker has developed a reputation for affordable gadgets that perform better than they have any right to. The PowerPort Solar is a great solar charger, even more so for its low price point, and it’s the one we recommend most people in the market for one of these devices to look at first.
Let’s get the negatives out of the way first, because if they’re dealbreakers for you, it’s best to know them upfront. First, there are no USB-C ports, so you’ll have to keep a USB-C to A cable handy for your USB-C devices. Secondly, this charger is not water resistant, so you’ll have to be vigilant for rain. The panels themselves have an IPX4 rating, but not the electronics box.
If you’re happy with these small compromises, you’ll find a lightweight, foldable, and flexible solar charger with a built-in kickstand and enough power output to charge most phones and tablets at rates similar to wall chargers. Each port can provide up to 12W of power. Considering that common “fast” chargers are 18W and typical iPad wall chargers are also 12W, this isn’t a bad result.
While it would have been nice to get more than 12W for single-device charging, Anker makes up for it thanks to its auto-resume charging if the sun is blocked temporarily. Whether you’re camping or want a backup power solution to keep in your car for an emergency, this is a fantastic choice.
Solar Charger, Anker 24W 3-Port USB Portable Solar Charger with Foldable CIGS Panel for Camping, PowerPort Solar for iPhone 12/SE/11/XS Max/XR/X/8, iPad, Samsung Galaxy S20/S10/S9/S8, and
The Anker PowerPort strikes the perfect balance between price and performance. It’s thin, flexible, and supports multi-device charging with auto-resume if sunlight is interrupted. It’s not 100% water resistant, but in every other way it’s a great deal.