1/2aa LoRa node ndir Z-16 power problems

#1

Hello, i want to build simple fire sensor, i have stm31 temp/hum and z-16 co2, so the problem is, z-16 minimum voltage is 4V, but when 1/2aa node power from 3.6V 1/2aa lithium battery it gives only ~2.5-2.8 Volts, i tried boost converter, but node can’t read values, i tried separated batteries for ndir z-16, and uses transistor to turn it on and off, and it again can’t read values, when i use separated battery and it always power the sensor, only then it works

#2

how can i solve this problem

#3

Isn’t the z-16 working voltage 4.5 V ~ 5.5V DC?

#4

yes it is, but i need to use it by 1/2aa node