IBM ThinkPad 600 - Chapter 3. Protecting Your Computer

Battery Pack
The ThinkPad computer uses a lithium-ion (Li-ion) battery pack that
meets the following electrical specifications:
Figure 1-10. Lithium-Ion Battery Pack Specifications
Nominal Voltage +10.8 V dc
Capacity (average) 3.2 ampere hours (AH)
Protection Overcurrent protection
Overvoltage protection
Overdischarge protection
Thermal protection
1-12 System Overview