Use ac power
When the battery power is low, charge your battery by connecting your computer to ac power.
The battery is fully charged in about two to four hours. The actual charging time depends on the battery capacity, the physical environment, and whether you are using the computer.
Battery charging is also affected by its temperature. The recommended temperature range for charging the battery is between 10°C (50°F) and 35°C (95°F).
Use P-to-P 2.0 charging function
Both the USB Type-C connector (USB 3.1 Gen 1) and the Thunderbolt™ 3 connector (USB Type-C) on the computer feature the Lenovo-unique P-to-P 2.0 charging function, which enables one computer (A) to supply power to another computer (B) through a USB Type-C to USB Type-C cable when no ac power is available.
To use the function, ensure that:
The selected connectors support the P-to-P 2.0 charging function and power delivery function.
The remaining battery power of computer A is at least 30% and is 3% higher than that of computer B. Once the remaining power of computer A is lower than 30%, it stops supplying power to computer B. To check the battery status, see Check the battery status.