Hello Nordic Support Team,
We are currently developing an IoT product using the nRF9151. In our application, the device wakes up once per day, transmits a small amount of data to the server, and then returns to a low-power state for the remainder of the day.
Our current understanding is that the nRF9151 consumes approximately 2.7 µA while in PSM mode. Therefore, one possible approach is to keep the modem in PSM for the rest of the time after data transmission.
However, we are also considering an alternative approach where we completely cut the power to the nRF9151 after transmission and power it on again only when the device needs to send data the next day.
We would like your guidance on which approach is recommended for optimal battery life and system reliability:
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Keeping the modem in PSM mode for the entire idle period (~24 hours).
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Completely removing power from the module and powering it on once per day before transmission.
From our observations, a full power cycle requires around 20–30 seconds for modem initialization, SIM initialization, network search, and network attachment, whereas waking from PSM appears significantly faster.
Could you please advise which approach is generally recommended for ultra-low-power IoT devices with very infrequent transmissions (once per day)? Additionally, are there any impacts on network registration, battery consumption, or modem longevity that we should consider when choosing between these two approaches?
