B4R Tutorial How to calculate device's battery lifetime ?

Battery Life Calculator

If you want to know how many hours your battery will run before discharging, give this battery life calculator a try.

www.omnicalculator.com

Say, device with tiniest MCU (needed just 2 mA current for work) powered by CR2032 battery (of 200 mAh capacity) and sleeping almost 5 mins (298 seconds of 300 with total consumption of just 1 microAmpere during sleep), but awaked just for 2 second work - should be OK during ~1.5 years.

Battery life = Capacity / Consumption × (1 - Discharge safety),

Average consumption = (Consumption1 × Time1 + Consumption2 × Time2) / (Time1 + Time2),

battery life = battery capacity / device consumption × (1 - discharge safety)