The BatPack stores energy and is worn on the back. It is made from 6 RE Batteries, a Circuit, and a Tin ingot. It holds 60,000 EU. It's charged like a normal battery. You can charge it in a BatBox or other energy storage device, as well as any type of Generator, Another way of slowly but efficiently charging your BatPack, is wearing Static Boots or a Solar Helmet. It can be upgraded into a LapPack using Lapis Lazuli blocks and an Advanced Circuit.
You wear a BatPack like you would with a ChestPlate, Although it has NO armour value.