A:AnswerUser Manual states any bluetooth enabled cell phone but also says - "...If you have trouble paring your cell phone, it may not be compatible with your ATT phone set (then lists several models...") Check the Bluetooth Compatibility list at www.telephones.att.com/bluetooth.
A:AnswerI've had one of these AT&T phones for several years and the rechargeable batteries that come with the unit for the handsets have lasted for four or five years. If needed, they're available online and very reasonably priced.