18650 battery powered Arduino DS18B20 temperature sensor would lost on average 2 years without to re-charge or replace the battery. It is best to use 3.3v Arduino Pro Mini with lower clock speed to conserve battery. To optimize battery life further you can remove power LED and status led connected to Arduino pin 13.

18650 battery powered temperature sensors are feed power to Arduino mini through raw pin utilising onboard voltage regulator. I have these temperature sensors running over 16 months now and battery is still 96%.

See below the real picture of my One Wire ds18b20 temperature sensor running on 18650 battery for over 16 month and battery still at 96%.

Wireless Temperature Sensors for Hot water

Wireless Temperature Sensors for Hot water

If you want to make your own temperature sensors take note of wiring connections for nRF24L01 to Arduino and One Wire DS18B20 temperature sensor.

DS18B20 with Arduino and nRF24L01

DS18B20 with Arduino and nRF24L01

18650 Battery Powered DS18B20 Temperature Sensor

18650 Battery Powered DS18B20 Temperature Sensor

Arduino Sketch for DS18B20 1-Wire digital Temperature Sensor

Here is MySensors sketch i’m using for low power DS18B20 1-Wire digital temperature sensor node, make sure you modify your node id as per your needs and not to have all temperature sensors nodes with same id.

For more information about NRF24L01+ connection with Arduino please check this link

If you want to have One Wire DS18B20 Temperature Sensor connected directly to Raspberry pi GPIO pin then follow this post DS18B20 Temperature Sensor with Raspberry Pi for more details instructions and you need to follow One Wire Temperature Sensor – DS18B20 to MySQL/MariaDB Database in order to save all temperature reading to MySQL/MariaDB database. All comments and suggestions are welcome.