X1 carbon gen 7 battery life July 8, 2019 16 32 64 128 X1 carbon gen 7 battery life reddit Thinkpad x1 carbon gen 7 battery life Lenovo thinkpad x1 carbon gen 7 battery life Thinkpad x1 carbon gen 8 battery life X1 carbon 6 gen X1 carbon gen 6 in 2022
