Lenovo 019923U, Hardware Maintenance Manual

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3. If the indicator still does not turn on, replace the battery pack.
4. If the indicator still does not turn on, replace the system board. Otherwise, refer to “Checking the
backup battery” on page 36.
Checking the battery pack
Battery charging does not start until the Power Manager Battery Gauge shows that less than 96% of the
total power remains; under this condition the battery pack can charge to 100% of its capacity. This protects
the battery pack from being overcharged or from having a shortened life.
To check your battery, move your cursor to the Power Manager Battery Gauge icon in the icon tray of the
Windows taskbar and wait for a moment (but do
not click), and the percentage of battery power remaining
is displayed. To get detailed information about the battery, double-click the Power Manager Battery
Gauge icon.
Note: If the battery pack becomes hot, it may not be able to charge. Remove it from the computer and leave
it at room temperature for a while. After it cools down, reinstall and recharge it.
To check the battery pack, do the following:
1. Turn off the computer and disconnect the ac power adapter.
2. Remove the battery pack and measure the voltage between battery terminals 1 (+) and 7 (-). The
following correct voltages are shown in the following table:
Terminal Voltage (V dc)
1 + 0 to + 12.6
7 Ground (-)
1(+)
2(+)
3
4 5
6(-)
7(-)
3. If the voltage is less than +11.0 V dc, the battery pack has been discharged.
Note: Recharging will take at least 3 hours, even if the indicator does not turn on.
If the voltage is still less than +11.0 V dc after recharging, replace the battery.
4. If the voltage is more than +11.0 V dc, measure the resistance between battery terminals 5 and 7.
The resistance must be 4 to 30 K Ω. If the resistance is not correct, replace the battery pack. If the
resistance is correct, replace the system board.
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 “1110 Backup battery” on page 74).
5. Measure the voltage of the backup battery. See the following figure.
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Hardware Maintenance Manual