To achieve this, devices are generally programmed to go into deep sleep mode when not transmitting messages, maximizing battery life. The longevity of any node is still determined by the capacity of its battery, but going to sleep for extended periods will dramatically extend charge cycles.
Also, the LoRa signal itself doesn’t require a whole lot of power to generate and transmit. That means, even when the system is active and transmitting, power consumption is kept at a trickle. With a minimal amount of software tinkering, the Strata node from Gumstix idled at 20 mA in “idle” mode and topped out at less than 110 mA during transmission.