Using a Primary Battery to Power a Wireless Valve for Smart Irrigation Systems in Agriculture

In this work, the power management (PM) system to drive long range wide area network (LoRaWAN) latching solenoid valves (LSVs) for automated irrigation systems is studied in detail. The objective is to optimize the use of a supercapacitor and a boost converter, allowing to drive the LSVs from a small primary battery, even a button cell, to reduce installation costs and battery environmental impact issues. Two different LSVs were analyzed, one requiring a 12 V-1 A high-current pulse to be activated, while the second one requires a 9 V-1.8 A pulse. Detailed supercapacitor, converter, and leakage measurements are presented, allowing to properly optimize the circuit design and PM system. Following the proposed guidelines, a wireless solenoid valve can be operated for five years from a single 1/2AA LiSOCl₂ primary battery.