IBM THINKPAD S05L-1270-01 - Manual (Page 145)

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 overcharged 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:
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.
Note: In this case, the battery pack is
over-discharged. It takes at least 2 hours to
recharge the battery pack even if the indicator
does not turn on.
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.
4. If the voltage is more than + 11.0 V dc, measure the
resistance between battery terminals 3 and 4. The
resistance must be 4 to 30 K ohm.
Terminal Voltage (V dc) / Signal
1 + 0 to + 13.5
2 Send
3 Thermal
4 Ground ( − )
5 Select
ThinkPad 560, 560E (2640) 133