diff --git a/Firmware/src/secconfig.h b/Firmware/src/secconfig.h
index 3b85c21..10ea312 100644
--- a/Firmware/src/secconfig.h
+++ b/Firmware/src/secconfig.h
@@ -31,6 +31,10 @@
      If you want to use DS18B20 sensors, the Onewire Library requires a clock frequency of 8MHz. 
      The value in platformio.ini must be adjusted accordingly
 
+     DS18B20 minimum operating voltage is 3V.
+     CR2032 may not be sufficient to operate the sensor.
+     Use a 3.6 V power supply if necessary
+
      #define	DS18B20_PIN	PIN_A0 - DS18B20 Temperature sensor(s) connected on D10/ATtiny pin13  
      
      Currently 2 sensors are implemented, for more sensors either copy the lines or improve the code