Portable power! Charge your cell phone, iPod and other small electrical devices more than 10 times while on the go. Perfect for camping, music festivals and emergency use, the Coleman 4D XPS Portable Energy Pack operates on 4 D-cell batteries (not included) -- or use it with the Coleman XPS Rechargeable Battery Pack (sold separately). The Coleman Portable Energy Pack includes standard 3.1mm and USB jacks for all your devices, with a built-in storage compartment for charging cords. On a set of 4 D batteries, the Energy Pack will charge a fully-depleted cell-phone battery about 20 times! The Energy Pack is a must-have for regions where alkaline batteries cost more than the products that use them.