This is a good little charger at a great price. The charger comes with a set of 2 batteries for 2 controllers. The charging device connect to the port on the top of each controller, the same ports that are used by the "charge and play" cables. The charger can charge 2 controllers simultaneously as long as neither controller doesn't have anything attached to the bottom port of either controller. That is to say that if either of your controller has a keypad attached to it then the attaching angle of the charger prevents charging 2 controllers at the same time. Pros: 1. Charging unit comes with 2 rechargeable batteries. 2. The charger can charge 2 controllers simultaneously. 3. Charging is relatively fast compared to other battery chargers. Cons: 1. Batteries MUST be in a controller to be charged. 2. Only one controller can be charged at a time if any added devices like the keyboard attachment are on a controller due to the angle of connection to the charger base unit. 3. Batteries do not work with & are not recognized by ALL Xbox 360 controllers (ether controller won’t turn on or you will get strange light patterns from the controller & it won’t connect or the controller isn’t recognized by the Xbox 360 console when the included rechargeable battery is installed into a controller unit. Included rechargeable batteries only work with 3 out of 5 of my Xbox 360 controllers.)