The Power Consumption of End Devices
Not surprisingly, electronic devices require electric energy to function. For most people, this is as simple as plugging a household device into a wall socket. For other scenarios, energy may need to be provided in another manner if power is not readily accessible. In such cases, devices may need to get energy from a battery, generator, or some other source.
Because energy may be limited or not always readily accessible, standby (or sleep) modes have been introduced. In the European Union (EU), regulations require that devices in standby mode must require less than one watt of energy per hour. In an off-the-grid situation, electric power cannot be assumed to be generated at all times, so a battery needs to be present. To extend the life of the battery, it is imperative that such devices are put into sleep mode.
An advantage of putting a device to sleep, rather than shutting it off completely, is that sleeping devices can be activated more quickly than those that are fully shut down.