I 've made a device with Arduino and Lora RA-01 module.
The transmitter is powered by a Li-Ion battery charged at 3.6V because Lora module cannot tolerate more than 3.6V.
When I give it to the client, he will charge the battery at full voltage, 4.2V.
So, I 'm thinking of putting at the output of the battery a zenner diode of 3.6V.
So that when the battery is over 3.6V the voltage will be limited at 3.6V.
And when the battery voltage drops at 3.6 the zener will tottaly stop conducting, which is extremelly important as it's a battery operated device and I mind power consumption a lot.
On the other hand I could use an LDO regulator, but I don't think I 'll gain anything.
What do you think?