What are the key application lifetime considerations?

For battery-powered systems such as mobile or portable designs, battery life, i.e. the interval at which the batteries must be changed or charged, is an important factor in system design.

In addition to the capacity of the battery, application-specific features must also be taken into account. They have a significant influence on the achievable running times:

• Transmit/receive interval
• Network topology
• Idle- and standby currents, as well as feasible leakage currents
• Operation currents during sleep and operating stages

Generally valid statements can be difficult to make. However, it can be stated:

• The more time the device spends in sleep mode, the longer the battery life. However, improvements due to wake-up intervals greater than 10 minutes are negligible.
• The larger the built-in battery, the longer it lasts. Equally important, however, is the hardware design, where energy can be saved, for example, by selecting efficient voltage regulators or even by dispensing with them.
• Carefully verify and analyze battery-powered devices throughout the entire design phase and incorporate sophisticated firmware models to reduce power consumption.
• If routing or repeating is required in the wireless network, it helps if those functional nodes are mains or bus powered to keep a reliable networking communication. On demand integration of rechargeable emergency battery scheme makes the overall design more reliable.