What is a portable solar phone charger?
A solar phone charger is basically a power bank that’s charged with sunlight (or UV light). Rather than plugging your power bank in and charging it up before a day out or a big trip, you can just leave it outside to soak up some rays.
This is particularly useful if you’re traveling, camping or if you’re staying somewhere without any power outlets.
Some solar portable chargers are hybrids, in the sense that they can also be charged electrically. This means it can be charged indoors overnight, or on days that aren’t particularly sunny (although most solar USB phone chargers can still charge in cloudy conditions).
The vast majority of solar chargers are actually just normal power banks that have been fitted with a solar panel on one side which lets the device trickle charge an internal lipo battery from the solar panel.
Where to buy a portable solar charger for your phone?
You can find solar portable chargers in most tech stores, but physical stores usually only have one or two power banks in stock. If you want to browse a wide range of solar phone chargers, it’s worth buying one online, especially because you can read reviews and compare.
Amazon in particular is a good place to buy portable solar chargers. There are hundreds of different solar portable chargers to browse, so you’ll have more to choose from, and you can easily check out the specs and reviews. We’ll get into the best options in a minute, but first, let’s take a look at what to look for in a solar power bank.
How do I choose the best solar charger?
Different solar phone chargers have different battery sizes and different solar panel surface areas. The battery size determines what the power bank can charge, and the recharging frequency. And the solar panel surface area affects how quickly it can recharge itself. The other thing to consider is that the more power you want the charger to have, the heavier it usually becomes.
Choosing the right battery capacity
If you want to find the best solar charger for you and your lifestyle, you’ll need to decide how long you’ll need the battery to run for. If you want a solar phone charger that’s going to last for more than just a single phone charge, you’ll need one with a relatively high ‘mAh’ or capacity.
‘mAh’ stands for milliampere hour, and it basically describes the battery’s capacity, meaning how long it can constantly charge something for before running out. So the higher the mAh, the longer the charger can run for before needing a recharge.
However, bear in mind that the mAh, the longer the power bank will take to charge. Think of it like a giant water bottle. A bigger bottle holds more water, but it also takes that bit longer to fill up. Usually, a single phone charge uses 2000 mAh, so a 10,000 mAh solar portable charger would be able to charge a phone 5 times. Most solar powered chargers are either 10,000 or 25,000 mAh with the higher spec ones reaching as high as 30,000 mAh.
Compact design vs. fast charging
You should also think about whether you want a compact design, or a charger that unfolds, giving you a larger surface area of solar panels.
A smaller power bank will have smaller solar panels, so it’s going to take a while to charge. A foldable solar charger will be slightly bulkier in design, so a bit more difficult to pack, but it’s much easier and quicker to recharge from solar power because there are more panels charging the same internal battery.
Solar vs. hybrid
You’ll also have the choice between a charger that can only be powered with solar energy, or a hybrid charger that can also charge on electricity through USB. The best ones are the hybrid unfolding panels, because they not only charge from the sun faster, but they can also be charged from a traditional micro USB if there’s not enough sun on a given day.
How long do solar power banks last?
How long your solar charger lasts will depend on the mAh. A power bank with a lower mAh will only give you a few phone charges. A power bank with a higher mAh will last a lot longer. That’s a very simple way of looking at it, but that’s generally how it works. Of course if you’re charging smaller devices like iPods or headphones, they’ll charge faster, and not eat too much of the power banks overall power.
A 10,000 mAh charger will charge your phone (a typical iPhone like an iPhone 6+) around 4-5 times, whilst a 25,000 mAh charger will charge your phone just over 12 times. Even this varies slightly though, as certain power banks and batteries have different levels of quality in their production, so you might find that certain brands perform better than others.
Once your solar powered charger is fully charged, it will usually retain its full charge for about 4-6 weeks. So it doesn’t matter too much if you don’t use it straight after charging it. That being said, like any high power batteries (especially Lipo batteries) they do lose charge over time, and it’s not advised to leave them long periods of time without discharging or using them. They work best with ‘regular average’ use.
For most of us, this just means using the power bank at least once a week to keep the battery working in top condition. There’s a life to every battery and solar power banks are no different, but you can lengthen that life by charging it when it needs it. You can also improve overall life by not running too many devices from the power bank at the same time.
Will a solar charger work indoors?
The solar power you need to charge your power bank should ideally come from natural sunlight only. However, if the weather isn’t great, you might want to charge it indoors.
If your power bank can be charged with solar energy or electricity, you can easily plug it into a power source.
But you can also sometimes find solar energy indoors too. Fluorescent and incandescent light bulbs mimic the sun’s spectrum, so they can charge solar powered devices, although usually it’s more efficient to just plug it into a USB port.
Solar panels are by design, not 100% efficient, and you’ll never find a solar panel that takes 100% of the solar energy that hits the panel, and converts it into power. So when you’re charging it using artificial light which gives off a lot less energy than the sun, even the best solar charger won’t work as well.
That’s why they have efficiency ratings, whereas plugging it into a Usb charger will usually charge the power bank with at least 90-95% efficiency. What you can do however, is charge the power bank on a windowsill if it’s cloudy outside.
Can you charge a solar charger through a window?
If you don’t want to venture outside to place your solar portable charger in a sunny spot, it can still soak up sunlight through a window. So you can place them on window ledges in your home, or even on the dashboard of your car.
However, it won’t charge as quickly this way. It will take up to three times longer to charge a solar power bank through a window, thanks to the iron content in the glass. You might struggle to charge it all if the window is tinted. This is something to really consider, when deciding between a waterproof power bank or a non waterproof one. Waterproof power banks are better usually because you don’t need to worry about protection from rain if you’re leaving it outdoors.
Even leaving a power bank outdoors with a plastic covering can reduce the efficiency and make it take longer to charge. This can be annoying, especially if you have no choice but to leave it outdoors, and you really need it to charge fast. The most effective option is just to leave a fully waterproof solar power bank outdoors in direct sunlight for a long period of time.
Can I take a solar charger on a plane?
Just like standard power banks, you can take solar powered chargers on planes, as long as you pack them into your cabin luggage. If you accidentally leave a solar charger in your checked baggage, you risk having it confiscated or destroyed by airport security. They also really need to be able to see the little sticker on the back showing the capacity and voltage of the power bank. Sometimes they throw the device away or refuse to let it through security if they can’t determine the mAh and voltage.
Also some airlines, airports and countries have restrictions on what types of power bank you can actually travel with. Some airlines don’t let you onboard with power banks that have above 25,000 mAh power. Others have voltage restrictions, or even cell restrictions.
How do solar portable chargers work?
Put simply, the power bank captures some of the sun’s energy and converts it into electricity. The way it works in more detail, is the solar powered charger is lined on one side with photovoltaic cells which capture the suns energy and use it to trickle charge the internal battery of the device.
But because the lipo batteries in solar phone chargers usually have a high capacity (meaning the battery lasts longer), and the solar panels are often fairly small, the process can take a little while. In fact, it can take several hours, or even a full day, to fully charge the internal battery.
The process isn’t as efficient as electrical charging, as you lose a lot of power when the solar energy is converted. But it’s often more convenient and sustainable. The best way to speed up the charge time is to buy a solar phone charger with additional fold out solar panels.
What is the best solar charger for backpacking?
When you’re backpacking, you want a solar portable charger that’s waterproof. You often end up hiking or walking around and being caught out in a shower, so you really need a waterproof solar powered charger. You should also look for a device that can clip onto the outside of your backpack so it can charge while you walk.
What is a trickle charger?
Trickle charging refers to the way solar power banks recharge their internal lipo battery. It’s a slow process which essentially stops the battery from depleting its power source over time. This means it can slowly add charge to the battery and eventually (over the course of several hours) fully charge the cells. Most solar power banks are trickle chargers, that charge an internal lipo battery.
The solar portable chargers that don’t do this trickle charging are usually the more expensive fold-out solar power sources that have a transformer box with USB ports in the side. These are bigger and heavier, but they perform several times better and faster than the compact ‘power bank’ type solutions. It’s a battle between practicality/size, and performance.
Can you charge solar panels with a light bulb?
Some solar portable chargers can be charged with a light bulb, if the bulb is strong enough. But for the most part, it’s just not as effective as plugging it into a USB port. It’s usually the bigger, more powerful fluorescent bulbs that are able to charge solar banks.