Checking The Backup Battery - Lenovo ThinkPad G41 Hardware Maintenance Manual

Checkout guide
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 4 and 5. The
resistance must be 4 to 30 K .
If the resistance is not correct, replace the battery
pack. If the resistance is correct, replace the system
board.

Checking the backup battery

The backup battery is rechargeable.
To check 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 66).
4. Remove the backup battery (see "Checking the battery
pack" on page 39).
5. Measure the voltage of the backup battery. See the
following figure.
v If the voltage is not correct, recharge the backup battery
by connecting the ac adapter to the computer for one
hour.
v If the voltage is still not correct, replace the backup
battery.
40
ThinkPad G40, G41
Terminal Voltage (V dc)
1 + 0 to + 12.6
(Li-ion)
5 Ground
Terminal Voltage (V dc)
+ +2.5 to +3.2
- Ground