Lutron Aurora dimmer knob (Z3-1BRL) has missing battery functionality

[fractalcounty]

What happened?

Despite being supported in zigbee2mqtt and its hardware itself supporting the functionality, the Lutron Aurora Z3-1BRL dimmer knob does not expose or report remaining battery % in zigbee2mqtt.

What did you expect to happen?

The Z3-1BRL should expose and report battery usage % in the zigbee2mqtt frontend automatically upon device adoption similar to other battery-powered devices like the Philips Hue dimmer switch. Additionally, a battery sensor should be automatically created in HomeAssistant.

A similar issue was outlined 3 years ago in #9736, but its scope was limited to creating a custom converter for the Z3-1BRL to manually expose battery usage. Despite being marked as completed, no out-of-the-box functionality relating to battery usage exists for the Z3-1BRL to this day (despite the device fully supporting it). Users have continued to observe this problem as recently as this week, so it appears to just be a case of missing functionality that's slipped under the radar over the years.

I suspect this may have something to do the fact that the Z3-1BRL seems to only want to communicate with zigbee2mqtt while in an "awake" state (i.e after being physically pressed or rotated), as outlined in a similar (now stale) issue I opened for the Z3-1BRL in 2021 (see #20668). If this is a case, perhaps battery reporting could occur whenever the device is in its active state?

How to reproduce it (minimal and precise)

1. Factory reset the Z3-1BRL dimmer switch
2. Add the custom legacy: false device option to its configuration
3. Permit joining in zigbee2mqtt and wait for device adoption
4. With the Z3-1BRL in its awake state, bind the PowerCfg cluster's batteryPercentageRemaining attribute to the coordinator endpoint in the device's "Reporting" tab

Zigbee2MQTT version

1.42.0-dev commit: c3b4628

Adapter firmware version

20240710

Adapter

SMLight SLZB-06 (zStack3x0)

Setup

Add-on in Home Assistant OS VM via Proxmox VE on a Intel N100 mini PC

Debug log

N/A

[ajma]

I finally got rid of my hue hub and moved it all to zigbee2mqtt and this is the last issue I'm dealing with. I have three of these buttons and I'm not able to figure out how to get battery readings

[x10]

I also recently started using these dimmers and it is the only device that doesn't report its battery level in my set up.

[Koenkk]

Could you check if the issue is fixed with the following external converter:

• save this as file next to configuration.yaml as ext_converter.js
• add it to configuration.yaml:

external_converters:
  - ext_converter.js

• start z2m
• in the frontend, check if the description of this device now ends with CUSTOM (this indicates the external converter has been loaded correctly)
• reconfigure the device via the frontend (yellow refresh button), make sure to wake up the device right before doing so (by pressing a button on it)
• check if issue is fixed

[fractalcounty]

ext_converter.js seems to have done the trick and battery is being reported for my Z3-1BRL devices. Thank you! I'll keep an eye out for any issues, but everything seems OK so far.

Also, no idea if this is relevant, but saving the script at /config/zigbee2mqtt/ext_converter.js and adding it as an external converter in the adjacent zigbee2mqtt configuration.yaml file had no effect after restarting Home Assistant & zigbee2mqtt. Even listing nonexistent scripts with arbitrary names as external converters in configuration.yaml produced zero errors or relevant debug messages in the logs.

I ended up just adding the external converter by sending a MQTT message to zigbee2mqtt/bridge/request/converter/save with the payload containing the script contents, which actually ended up saving it to /config/zigbee2mqtt/external_converters/ext_converter.js instead. I most definitely just missed something in the docs or misconfigured something, though.

[Koenkk]

Integrated the fix, thanks!

Changes will be available in the dev branch in a few hours from now.