2x USB 2.0 (15") or 3x USB 2.0 (17") 2x USB 2.0 (13" and 15") or 3x USB 2.0 (17") 2x USB 3.0 Mini DisplayPort Thunderbolt port Gigabit Ethernet , Firewire 800 , Audio line in/out Battery ( lithium polymer , non-removable except in original 15") N/A 58 Wh (13") 63.5 Wh (13")