Power

How to estimate battery life before you build anything

A simple current-budget model you can build in a spreadsheet. Includes worked examples for a BLE sensor node and a display-driven consumer device.

Pogot Studio Engineering · 2025-10-10 · 6 min read

How to estimate battery life before you build anything

Battery-powered IoT sensors and wearables must balance active current draw with deep sleep strategy.

Creating a Current Budget Model

  1. Active State: Measure or locate the MCU active current + radio TX/RX power draw.
  2. Sleep State: Calculate leakage current from MCU sleep modes, LDO quiescent current, and sensor standby.
  3. Duty Cycle: Determine how many milliseconds per hour the device spends transmitting vs sleeping.