Checking Operational Charging; Checking The Battery Pack - Lenovo B575e Hardware Maintenance Manual

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

Battery charging does not start until the power meter shows that less than 95% 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 meter icon in the icon tray of the Windows
and wait for a moment (but do not click it), and the percentage of battery power remaining is displayed. To
get detailed information about the battery, double-click the power meter icon.
Note: If the battery pack becomes hot, it may not be able to be charged. 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. Power off the computer.
2. Remove the battery pack and measure the voltage between battery terminals 1 (+) and 7 (-). See the
following figure:
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.
Terminal Voltage (V dc)
1 + 0 to + 14
7
Ground (-)
®
taskbar
.
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