Skip to main content

E10 — BATTERY_INIT_FAILED

Hardware version

This error only occurs on v4 hardware.

The BQ27441 fuel gauge IC failed to initialise over I²C.

What happens​

battery_read_task exits immediately. The device loses battery state-of-charge monitoring — the battery percentage will not be shown on the display or reported to the server. All other functionality continues normally.

Possible causes​

  • The BQ27441 fuel gauge is not responding on the I²C bus. This can happen if the battery was disconnected before boot.
  • The fuel gauge IC is defective.

How to fix​

  1. Ensure the battery is connected — If the battery was removed or disconnected, reconnect it and reboot. The firmware even logs "Battery was removed before boot!" if state-of-charge reads as 0 after init.
  2. Reboot the device — A fresh boot retries the task.
  3. Contact support — If this error appears consistently with the battery properly connected, the fuel gauge IC may be faulty. Open an issue on GitHub.