Lenovo B475e Notebook - Manual (Page 37)

Note: Noise from the ac power adapter does not always indicate a defect.
Checking operational charging
To check whether the battery charges properly during operation, use a discharged battery pack or a battery
pack that has less than 50% of the total power remaining when installed in the computer.
Perform operational charging. If the battery status indicator or icon does not turn on, remove the battery
pack and let it return to room temperature. Reinstall the battery pack. If the charge indicator or icon still does
not turn on, replace the battery pack.
If the charge indicator still does not turn on, replace the system board. Then reinstall the battery pack. If it is
still not charged, go to the next section.
Checking the battery pack
The battery status icon in the Windows ® notification area displays the percentage of battery power remaining.
To check for detailed battery status information on the Windows operating system, do the following:
• Windows 7: Launch the Power Manager program and click the Battery tab.
• Windows 8:
– Press the recovery button to launch the Lenovo Solution Center program, and then click Battery.
– Open the Lenovo Settings program, and then click Power.
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 (-). See the
following figure:
Terminal Voltage (V dc)
1 + 0 to + 14
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 pack.
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.
Chapter 3 . General checkout 31