Simple concept - a battery in a bag - but this bag contains a lightweight, LIthium 10 AH battery in the sturdy PowerPort bag. Lithium batteries are noted for their high performance, light weight and superior performance in cold temperatures. The bag is a padded heavy duty nylon case with sturdy buckle-down lid with extra room inside for accessories, and an adjustable strap handle to make it easy to carry. It's weatherproof and tough. No charger supplied.