IBM THINKPAD 760C/CD (9546) - Manual (Page 286)

Perform operational charging. If the battery status
indicator does not turn on, remove the battery pack and
leave it to return to room temperature. Reinstall the
battery pack. If the charge indicator still does not turn on,
replace the battery pack.
Checking the Battery Pack: Battery charging will
not start until the Fuel-Gauge shows that less than 95% of
the total power remains; with this condition the battery
pack will charge to 100% of its capacity. This protects the
battery pack from being over-charged or having a
shortened life.
Do the following:
1. Power off the computer.
2. Remove the battery pack and measure the voltage
between battery terminals 1 ( + ) and 4 ( − ). See the
following figure.
1
2
3
4
5
Note
Signal lines, not used in these steps, are used for
communication between the system and the
battery.
3. If the voltage is less than + 11.0 V dc, the battery pack
has been discharged. Recharge the battery pack.
If the voltage is still less than + 11.0 V dc after
recharging, replace the battery.
Note
If the voltage of the battery pack is 0 V, it is not
defective.
Terminal Voltage (V dc) / Signal
1 + 0 to + 13.5
2 Send
3 Thermal
4 Ground ( − )
5 Select
274 IBM Mobile Systems - ThinkPad HMM Volume 3