Product Information : Microsoft Xbox 360 Play and Charge Kit
Manufacturer's product description
Recharge your Xbox 360 Wireless Controller while you play and kiss disposable batteries goodbye! Complete with a charging cable and rechargeable battery pack, the Xbox 360 Play and Charge Kit is all you need to juice up your Wireless Controller - even in the midst of battle.
Microsoft Xbox 360 Play and Charge Kit battery and charger - NiMH