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Fox Battery SOH sensor incorrectly uses device_class: battery, causing low battery alert on Home Assistant Maintenance dashboard #4485

Description

@apkehoe

Describe the bug
The sensor created by Predbat for Fox battery State of Health (example: sensor.predbat_fox_60kg7020641b143_battery_soh) is published with:

device_class: battery
state: 1.0 (representing 100% SOH as a fraction)
unit_of_measurement: *

Because it has device_class: battery, the official Home Assistant Maintenance dashboard (introduced in 2026.5) treats the value 1.0 as 1% battery and flags it as a low battery that needs attention.
This creates a permanent false “1 low battery” warning in the Overview summaries and in the Maintenance view.

Expected behaviour
An SOH (State of Health) sensor should not use device_class: battery.
Battery device class is intended for remaining charge percentage (0–100), not for health/scaling factors.
Suggested fixes:

Remove device_class: battery from SOH sensors, or
Use a more appropriate device class / no device class, and/or
Publish the value as a percentage (0–100) instead of a 0–1 fraction so it is less confusing even if the device class remains.

Predbat version

v8.47.7

Environment details

Fox KH7 inverter - vMaster: 1.60, vSlave: 1.02, vARM: 1.58
Fox battery - EP12 - BMS 1.012
Docker HA

Log file

predbat.log

Activity

  1. changed the title [-]FoxFox Battery SOH sensor incorrectly uses device_class: battery and breaks Home Assistant Maintenance dashboard[/-] [+]Fox Battery SOH sensor incorrectly uses device_class: battery and breaks Home Assistant Maintenance dashboard[/+] on Aug 11, 2026
  2. changed the title [-]Fox Battery SOH sensor incorrectly uses device_class: battery and breaks Home Assistant Maintenance dashboard[/-] [+]Fox Battery SOH sensor incorrectly uses device_class: battery, causing low battery alert on Home Assistant Maintenance dashboard[/+] on Aug 11, 2026
  3. gcoan commented on Aug 12, 2026

    @gcoan
    Collaborator

    updated title, it doesn't "break" the HA dashboard, it causes an unnecessary low battery warning which can be avoided

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