£4.50 each, either put one on each controller or charge one whilst using another. These are very good, bought two myself last year for slightly more.
Play and charge your XBOX ONE controller at the same time. Venom's Twin Rechargeable Battery Packs charge two battery packs from just one USB cable meaning that frustrating mid-game power loss is a thing of the past. The two powerful rechargeable battery packs provide maximum power for gameplay of up to 18 hours.
Play XBOX ONE whilst charging
Includes 2 metre dual charging cable, 1 metre split
Up to 18 hours gameplay