newegg via eBay offers the NYKO Charge Base for Xbox 360
, model no. 86074, for $19.99
with free shipping
. (Next Warehouse
has it for the same price.) That's the lowest total price we could find by $5. Each rechargeable battery purportedly powers a wireless controller for up to 25 hours and charges a single battery in 2 hours, or both batteries simultaneously in 4.