When the battery power is low, charge your battery by connecting your computer to ac power.
The battery is fully charged in about four to eight hours. If the power adapter shipped with your computer supports the rapid charge function, the battery is 80% charged in about one hour when the computer is turned off. The actual charging time depends on the battery size, the physical environment, and whether you are using the computer.
Battery charging is also affected by the battery temperature. The recommended battery temperature range for charging the battery is between 10°C (50°F) and 35°C (95°F).
The USB-C connector (USB 3.1 Gen 1) on the computer feature the Lenovo-unique P-to-P 2.0 charging function. When no ac power is available, this feature enables one computer to supply power to another computer through a USB-C to USB-C cable.
The selected connectors support the P-to-P 2.0 charging function and power delivery function.
Enter the UEFI BIOS menu. See Enter the UEFI BIOS menu.
Click to enable Always On USB and Charge in Battery Mode.
To use the function (when no ac power is available):
