- The amount of time a battery can power a portable phone once fully charged. This time is usually calculated for a telephone which is turned on and able to accept calls.
- The time a battery can power a device, such as a PDA, once fully charged. This time is usually calculated for a device which is turned on and able to function, but which is not used for any purpose.
- The time during which a component, circuit, device, piece of equipment, or system is in standby mode.