Checking The Backup Battery - Lenovo ThinkPad X1 Carbon Hardware Maintenance Manual

Checking the backup battery

To check the backup battery, do the following:
1. Disable the built-in battery. See "Disabling the built-in battery" on page 60.
2. Remove the backup battery. See "1090 Battery pack" on page 70.
3. Measure the voltage of the backup battery. See the following illustration.
• If the voltage is correct, replace the system board.
• If the voltage is not correct, replace the backup battery.
• If the backup battery discharges quickly after replacement, replace the system board.
28
Hardware Maintenance Manual
Wire
Voltage (V dc)
Red +2.5 to +3.2
Black Ground