CHOETECH B659 10000mAh Solar Power BankTwo Ways Of Recharging The Solar Power Bank itself can be recharged in two ways, either via USB cable or by taking it outside and letting the built in solar panel do its work. A wide variety of factors have an impact on how fast the sun is able to recharge your solar power bank, like the season, location, time of day, and of course cloudiness. High Battery Capacity The Solar Power Bank is equipped with a 20,000mAh lithium polymer battery, powerful