Charging Benches are usefull items added by Advanced Power Management - an addon for Industrial Craft 2. It allows allows you to charge up to 12 items simultaneously! It comes in three tiers, with similar charging restrictions, energy storage, and voltage limits to the storage unit each is built on.
The Charging Bench will automatically direct valid electrical items shift-clicked from your inventory into the charging area if there is space free with the excess being placed into the input slot. Once an item is done charging, it will be automatically moved to the output slot, and another item from the input slot will be added to the main area. For example, you can shift-click a full stack of RE-Batteries into the GUI and it will automatically unstack, charge them all and allow fast and easy collection by repeatedly shift-clicking the output slot.
While using the bench, you have quick access to your equipped armor and if you are wearing electrical armor, can shift click it directly into the bench. When it's done charging, simply shift-click it from the output or any other slot and it will automatically equip into the proper location!
Each bench has two indicators visible on the outside. The meter on the left reflects the energy stored, and the green activity light lets you know if your items are done charging without even opening the GUI.
Charging benches accept standard IC2 upgrades. The transformer upgrade allows lower tier benches to accept higher input energy and better battery-type items in the power slot. (Note that a Charging Bench exposed to unacceptably high voltage will break off onto the ground safely, ejecting any items it contained.) The energy storage upgrade increases the storage of the device, each bench gaining a different amount. The overclocker can dramatically reduce item charging time - but, as always with OCs, this results in increased energy consumption.
The input, output, and power slots are exposed to pipes, tubes and other devices. Input is on top, output is on bottom and the power slot is accessed from any side. Valid electrical items placed into the input slot will be moved to a charging slot, then moved to the output slot for retrieval once full. In this way, you can easily automate recharging of items!