Lenovo ThinkPad X390, Hardware Maintenance Manual, Page: 35 / 108

Attention: Lenovo has no responsibility for the performance or safety of unauthorized batteries, and
provides no warranties for failures or damage arising out of their use.
Move your pointer to the battery-status icon in the Windows notification area to check the battery status. The
battery-status icon displays the percentage of battery power remaining and how long you can use your
computer before you must charge the battery.
To check whether the battery charges properly during operation, do the following:
1. Discharge the battery until the remained battery power is less than 50%.
2. Connect the computer to ac power to charge the battery. If the battery status icon in the Windows
notification area indicates that the battery is not charging, remove the battery and let it return to room
temperature.
3. Reinstall the battery. If the battery is still not charging, replace the battery.
4. Check the battery status icon again. If the same error still exists, replace the system board.
Checking the coin-cell battery
To check the coin-cell battery, do the following:
1. Disable the built-in battery. See “Disable Fast Startup and the built-in battery” on page 64.
2. Remove the coin-cell battery. See “1080 Coin-cell battery” on page 71.
3. Measure the voltage of the coin-cell battery. See the following illustration.
Wire
Voltage (V dc)
Red +2.5 to +3.2
Black Ground
• If the voltage is correct, replace the system board.
• If the voltage is not correct, replace the coin-cell battery.
• If the coin-cell battery discharges quickly after replacement, replace the system board.
Chapter 3
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