Once a portable charger runs out of juice, you need to find an outlet to recharge it. Solar power banks, however, help you avoid this problem – they can be powered by the sun. Like solar chargers, the devices have built-in solar cells that capture sunlight and convert it into electrical energy to charge the devices. But unlike solar chargers, solar power banks are designed with a built-in battery to store the energy generated. This means that solar power banks do not need to be exposed to direct sunlight while charging your devices (as long as the battery is full), giving you more flexibility in terms of when and how you use it.
GO AHEAD Highly rated solar power banks | How to buy a solar power bank
You can keep a solar power bank in your emergency kit as a battery backup, or take it with you if you’re going outside for the day. And since a solar power bank stores energy, you can also use it to charge your devices indoors – solar chargers don’t give you that option because they only work when exposed to light of the sun. To help you choose a solar power bank, we consulted experts on their pros and cons, and the most important features. We’ve also rounded up highly rated models in a variety of sizes and power capacities.
What are solar power banks?
Solar power banks are designed with batteries to store the generated energy. You can plug your devices into the solar power bank and charge them. Then you can “recharge” the solar power bank’s battery by exposing its solar cells to sunlight. You can also plug some solar power banks into outlets to charge their batteries — in these cases, the sun acts as an alternative power source to the battery, explained Sudip K. Mazumder, a professor in the Department of Electricity and of electricity from the University of Illinois at Chicago. Engineering computer Science.
As we noted in our guide to solar chargers, many people refer to all chargers built with solar cells as “solar chargers”. But there is a distinction between solar chargers and solar power banks.
- Solar Power Banks store the energy generated in built-in batteries, so you can charge devices even when there is no sun.
- Solar chargers are designed without batteries and do not store energy. They should be exposed to sunlight when charging your devices.
Since solar power banks store the energy generated and therefore do not need to be exposed to sunlight while charging your devices, they give you more freedom than solar chargers (as long as you planned ahead, that is).
The Best Solar Power Banks
Since we don’t test solar power banks ourselves, we rely on expert advice and our previous reports on how to buy them to highlight the best ones. Experts recommended looking at device compatibility, power, and size to determine which model is right for you. Note that charge capacity is often measured in milliamp-hours (mAh) or watt-hours (Wh) – all of the solar power banks we recommend list capacity in mAh, but only some include capacities in watts. Below we highlight highly rated solar power banks in a range of sizes with varying capacities that align with expert advice.
BioLite 5+ Solar Panel
Ability: 5W, 3,2000mAh
Compatibility: 1 USB-A port
BioLite’s SolarPanel 5+ has a kickstand to support it, as well as an integrated sundial to help you align the solar cells with the sunlight. It also comes with a battery and charge indicator to see the strength of the sun and gauge your panel’s capacity. Additionally, the SolarPanel 5+ has a battery status button that tells you how much energy is stored in the battery. You can also charge the device’s battery by plugging it into an outlet. If you’re looking for a solar power bank with a larger capacity, BioLite offers the SolarPanel 10+, which can provide up to 10W of usable power.
Anker PowerCore Solar 10000
Ability: 12W, 10000mAh
Compatibility: 2 USB-A ports
In addition to the sunlight captured by the built-in solar cells, the brand said that you can also charge the battery of this solar power bank via a 10.5W wall charger. The PowerCore Solar 10000 is designed with a Built-in flashlight with three modes: low light, full light and SOS mode. Anker said the device has a solar efficiency of between 21.5% and 23.5% and is rated IP64, which means it’s dust and splash water resistant.
Hiluckey Solar Charger
Compatibility: 2 USB-A ports
Gordon previously recommended this Hiluckey solar power bank in our guide to solar powered gadgets. It features solar panels that fold out when you want to use them, and you can also recharge the battery by plugging it into an outlet. The solar power bank has a built-in flashlight with three modes: normal, SOS and strobe.
4PATRIOTS Portable Solar Power Bank
Compatibility: 2 USB-A ports
In addition to relying on the sun, the built-in battery in this solar power bank from 4PATRIOTS can be charged using an outlet. The brand said it has an IP67 rating, which means it’s resistant to rain and splashes. The solar power bank is designed with an LED flashlight with an SOS mode, as well as a battery indicator – when the power bank’s four blue lights are on, it is fully charged.
How to buy a solar power bank
When buying a solar power bank, experts tell us it’s important to think about what’s best for your needs and the devices you have. Also keep the price in mind – based on our research, we’ve noticed that devices with more or larger solar panels, as well as higher wattage capabilities, often cost more. Some solar power banks also feature built-in flashlights, which can come in handy in emergency situations such as power outages. Here’s what experts recommend to consider before you buy.
Power output and efficiency
Each device is designed with different size battery, which can guide your shopping. According to our previous reports, when it comes to power banks, charge capacity is often measured in milliamp-hours (mAh) or watt-hours (Wh) – all of the solar power banks we recommend list capacity in mAh, but only certain capacities included in watt.
- Watt hours (Wh) is a way of measuring charging capacity and will give you the best estimate of how much or how many times the charger can charge your device.
- Milliamp-hours (mAh) can be useful for comparing the capacities of different batteries. For example, a 5,000 mAh battery will deliver fewer charges than a 12,000 mAh model.
Typically, devices that are physically larger with higher power requirements have larger batteries and therefore require higher capacity chargers to speed up charging, Mazumder said. And if they’re listed, experts told us to compare the power of a solar power bank to your device’s charger when shopping.
“If it says ‘works best with a 27W+ charger,’ then look for the 27W+ charger,” Brad Saunders, president of the nonprofit USB-IF, said in our guide. portable chargers. However, Mazumder said lower capacity chargers can still power larger devices, just at a slower rate than higher capacity options.
Typically, Gordon explained, “a typical phone can charge at 5W, but most modern phones pack fast-charging capabilities up to 18W. And if you’re charging two devices at once, you’ll need enough power for both. Gordon also suggested checking a solar panel’s efficiency rating when buying – however, efficiency ratings aren’t always listed. He said the higher the percentage , the more solar power you can convert into charging power, and noted that anything above 20% efficiency is ideal.
Before buying a solar power bank, Mazumder said to make sure its ports are compatible with your electronic devices. Many solar power banks are built with USB-A ports, while some may come with an additional USB-C port.
Mazumder said people often buy new models of electronic devices and do so at a faster rate compared to buying solar power banks and other charging accessories. So the port type of your new phone may not match the port of your two-year-old solar power bank, requiring you to buy adapters to continue using it in the future.
Size and solar panels
According to Mazumder, the number and size of solar cells on solar power banks impact the amount of power they can generate.
When there are more solar cells on a charger – or larger cells – they can generate more power. Gordon noted that some solar battery banks only have one panel, which limits the amount of power they can generate. But more and larger solar cells can mean that the physical size of the solar power bank increases – you may have to decide if you want to prioritize size or wattage when shopping.
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