Checking the operational charging
To check whether the battery pack charges properly during operation, do the following:
1. Discharge the battery pack until the remained battery power is less than 50%.
2. Connect the computer to ac power to charge the battery pack. If the battery status icon in the Windows
notification area indicates that the battery pack is not charging, remove the battery pack and let it
return to room temperature.
3. Reinstall the battery pack. If the battery pack is still not charging, replace the battery pack.
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. Remove the coin-cell battery. See "1110 Coin-cell battery" on page 72.
2. Measure the voltage of the coin-cell battery. See the following illustration.
• 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.
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T470p Hardware Maintenance Manual
Wire
Voltage (V dc)
Red
+2.5 to +3.2
Black
Ground