The DS18B20 is a digital temperature sensor from Dallas Semiconductors, which is now part of Maxim (https://datasheets.maximintegrated.com/en/ds/DS18B20.pdf). The ...

How long can you keep an Arduino circuit running on three AA batteries? With careful design, [educ8s] built a temperature sensor that lasts well over a year on a single charge of three 2250 mAH ...