Checking The Backup Battery - Lenovo ThinkPad X131e Hardware Maintenance Manual

1(+)
3. Measure the resistance between battery terminals 5 and 7. The resistance should be 4 to 30 K Ω. If the
resistance is not correct, replace the battery pack.
4. Depending on the voltage that you measure, do one of the following:
• If the voltage is less than +11.0 V dc, recharge the battery pack. If the voltage is still less than +11.0 V
dc after recharging, replace the battery pack.
• If the voltage is more than +11.0 V dc, discharge the battery pack until the voltage becomes less
than +11.0 V dc, and then recharge the battery pack. If the voltage still is less than +11.0 V dc after
recharging, replace the battery pack.
Note: Recharging will take at least 3 hours, even if the battery status indicator does not turn on.
5. Replace the system board if the new battery pack is not charged.

Checking the backup battery

Do the following:
1. Power off the computer, and unplug the ac adapter from it.
2. Turn the computer upside down.
3. Remove the battery pack (see "1010 Battery pack" on page 58).
4. Remove the backup battery (see "1130 System board assembly, thermal fan assembly, and backup
battery" on page 74).
5. Measure the voltage of the backup battery. See the following figure.
• 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.
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Hardware Maintenance Manual
7(-)
6(-)
5
3 4
2(+)
Terminal Voltage (V dc)
1 + 0 to + 12.6
7
Ground (-)
Wire Voltage (V dc)
Red +2.5 to +3.2
Black
Ground