ORB Dual Controller Charge and Play Battery Pack (Xbox One)
About this item
Duo battery pack for your XBOXONE controllers
Recharge battery while you continue to play
High performance NiMH rechargeable batteriesLED charge indicators
Charged by USB cable via your XBOXONE or USB device
Includes 2 x 3m (10ft) charging cables
After doing a quick search the reviews aren't very favourable but considering the price I might balance it out.