---
title: "Fuel gauge"
canonical_url: https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/
last_updated: 2026-11-13
sdk_version: 4.44
---
# Fuel gauge

Source: https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/

`lib/fuel_gauge/` estimates the state of charge (SOC) of a single Li-ion or Li-po cell from periodic voltage, current and temperature measurements.

- [Introduction](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/introduction.md)
  - [Features](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/introduction.md#features)
  - [Cell](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/introduction.md#fuel-gauge-cell)
  - [Reported SOC](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/introduction.md#reported-soc)
  - [Time to empty and time to full](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/introduction.md#time-to-empty-and-time-to-full)
  - [Persistence](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/introduction.md#persistence)
- [Models](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/models.md)
  - [Thevenin](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/models/thevenin.md)
- [Characterization tools](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/tools.md)
  - [Bench runs](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/tools.md#bench-runs)
  - [Fit and replay](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/tools.md#fit-and-replay)
  - [Log format](https://developer.repebble.com/pebbleos/docs/libraries/fuel_gauge/tools.md#log-format)

Generated from PebbleOS [f4926c952](https://github.com/coredevices/pebbleos/commit/f4926c952bf9b82bce9e3cdb44645a59531c0ee9). This page is maintained in the pebbleos repository: [docs/libraries/fuel\_gauge/index.md](https://github.com/coredevices/pebbleos/blob/f4926c952bf9b82bce9e3cdb44645a59531c0ee9/docs/libraries/fuel_gauge/index.md).