The Goal Zero Guide 10 Plus Mobile Kit includes four rechargeable AA batteries and a 3.5 watt solar charging panel. The solar panel will charge the battery pack in about 3-4 hours, use them in the battery pack to power your USB devices or take batteries out and power your headlamp or other device. The mono-crystalline solar panel is the most efficient solar panel on the market and has a USB input so you can also use just the solar panel to plug your device directly in to recharge. A handy and bright built-in LED light is always with you on the top of the battery pack and can be used to find things in your dark backpack or purse. The light runs for over 150 hours before needing a charge.