Never run out of power again with the 8000 mAh Solar Power Bank from ToughTested. This portable battery pack features a built-in solar panel and is IP54 rated to be dustproof, shockproof, and rainproof. With an 8000 mAh capacity, it can fully recharge most smartphones three to four times. Also, it has two USB Type-A ports so you can charge two mobile devices simultaneously. When it's low on power, you can recharge it simply by leaving it out in the sun or by connecting a micro-USB cable to a computer or wall charger. Other features include built-in power indicators and a flashlight, which can come in handy in emergency situations.