Power output. If your device acts as a charger or battery bank, you’ll want to make sure it outputs enough power to charge your gadgets. A typical phone can charge at 5W, but most modern phones contain fast charging capabilities up to 18W. And if you’re charging two devices at once, you’ll need enough wattage for both.
Portability and durability. Since solar devices are meant to be used outdoors, there’s a good chance you’ll need to lug them around in your backpack. That means you’ll have to balance portability with the panel’s surface area and durability, both of which can add bulk.
Finally, keep your expectations in check — the smaller a solar panel, the less likely it’s going to be able to charge your device from 0 to 100 percent in a reasonable amount of time, especially underneath a cloudy sky. These conditions make it hard to predict how long any given product will take to charge your phone or tablet, but it’ll almost certainly be the better part of a day or more. It’s best to charge before you leave the house, and use your solar panel as a backup “top-off” measure that stretches your battery as long as possible, rather than your only source of power.
Best solar-powered charger: X-Dragon
For a simple solar panel that’ll charge any of your USB devices, check out X-Dragon’s 20W solar charger. It’s significantly more affordable than many of its similarly-powered competitors, while offering high quality solar cells with 22-percent to 25-percent efficiency. Two USB ports allow you to charge multiple devices at a time, and it folds up for easy portability — though it is rather large when unfolded.
Best solar-powered battery bank: Hiluckey
If you want something a bit smaller with a built-in battery — so it doesn’t have to be in the sun at the same time it’s charging your phone — check out this 20000mAh battery bank from Hiluckey. Unlike some solar battery banks that only have one measly panel, Hiluckey’s offering has three fold-out panels that allow you to capture more sun. It still isn’t enough to recharge as quickly as the X-Dragon set of panels, but it’s a good alternative if you want to store that energy in a portable battery bank.
Best solar-powered Bluetooth portable speaker: ABFOCE
Bluetooth speakers are a great way to bring the music outside… at least until the battery dies. This ABFOCE speaker extends the battery life with a built-in solar panel, which they claim can gain 30 minutes of playtime with 10 minutes in direct sunlight (provided you’re listening at a reasonable volume). It’s not one of the biggest and loudest speakers you can buy, but it’ll do the trick in a pinch — and it doubles as a battery bank for your phone, if you get into a jam.
Best solar-powered wireless keyboard: Logitech
If you’re all about that clean, cable-free workspace, a wireless keyboard is an obvious piece of gear. But plugging in to charge the battery (or worse, hunting for AAs in the middle of your work) can be a buzzkill — which is why Logitech built the K750 solar keyboard, which should keep itself charged by the light in your office.
Best solar-powered security camera: Ring
If you want a set of security cameras at home, but don’t have enough outdoor outlets in the right spots, Ring has you covered. Their Spotlight Cam is battery-powered, requiring a recharge every few months — or you can connect it to a Ring Solar Panel for built-in charging under the sun. If you aren’t a fan of Ring, there are third-party panels that connect to other cameras like Arlo, as well.
Best all-day solar-powered power station: Goal Zero
For something that lasts a little longer — and can power just about anything you have with you — Goal Zero offers a 150Wh power station that can charge anything from your USB-based phone to a full-sized device with three-prong AC power.
You can bundle it with Goal Zero’s own solar panel to add a bit of solar recharging, too. But remember: Don’t expect the solar panel to charge this huge battery quickly. Charge up at home, then use the solar panel to extend the station’s battery a bit longer with some extra sun power.