What are solar power banks?
Solar power banksare designed with batteries to store generated energy. You can plug your devices into the solar power bank and charge them. Then, you can “refill” 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 alternate source of energy to the battery, explained Sudip K. Mazumder, a professor at the University of Illinois Chicago’s Department of Electrical and Computer Engineering.
As we noted in our guide to solar chargers, many people refer to all charging devices built with solar cells as “solar chargers.” But there is a distinction between solar chargers and solar power banks.
- Solar power banks store generated energy in built-in batteries, so you can charge devices even when there’s no sun.
- Solar chargers are designed without batteries and do not store energy. They have to be exposed to sunlight when they’re charging your devices.
Since solar power banks store generated energy and thus do not need to be exposed to sunlight while charging your devices, they give you more freedom then solar chargers do (so long as you planned ahead, that is).
Best solar power banks
Since we don’t test solar power banks ourselves, we rely on expert guidance and our previous reporting about how to shop for them in order to highlight the best ones. Experts recommended looking at device compatibility, power and size to determine the right model for you. Note that charging capacity is often measured in either milliamp-hours (mAh) or watt-hours (Wh) — all solar power banks we recommend listed capacity in mAh, but only some included capacity in watts. Below, we highlight highly rated solar power banks in a range of sizes with varying capacities that align with expert guidance.
Capacity: 5W, 3,2000mAh
Compatibility: 1 USB-A port
BioLite’s SolarPanel 5+ has a kickstand to prop it up, as well as an integrated sundial to help you align the solar cells with sunlight. It also comes with a battery and charge strength indicator to see the strength of the sun and measure your panel capacity. Additionally, the SolarPanel 5+ boasts a battery status button that tells you how much power 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
Capacity: 12W, 10,000mAh
Compatibility: 2 USB-A ports
In addition to sunlight captured through the built-in solar cells, the brand said you can also charge this solar power bank’s battery via a 10.5W wall charger. The PowerCore Solar 10000 is designed with an integrated flashlight with three modes: low brightness, full brightness and SOS mode. Anker said the device has a solar efficiency rating of between 21.5 percent and 23.5 percent and is IP64-rated, meaning it's dust and water splash resistant.
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 features a built-in flashlight with three modes: normal, SOS and strobe.