The Charger provides a way to charge supported tools, and Certus Quartz Crystal.
Power can be provided via the top or bottom, via either AE2's cables, or other mod power cables. It can accept either AE2's power (AE) or Forge Energy (FE). Items can be inserted or removed from any side. Only the results can be removed, so no need for filters to prevent removing certus crystals instead of charged certus. Can be rotated with a Certus Quartz Wrench in order to facilitate automation.
To power it manually, place a Wooden Crank on the top or bottom and right-click it until the item is charged.
It also acts as the workstation for the Fluix Researcher.
As an example, the rotateability lets you semi-automate chargers like so: