ThermoPro Integration reporting incorrect Battery levels

[hareenl]

The problem

The ThermoPro Integration is constantly reporting a battery level of 50%. This occurs with TP359S and TP357S devices. I had 3 Thermpro devices go offline due to low battery and the last reported battery level shown on home assistant was also 50%.

What version of Home Assistant Core has the issue?

2024.6.4

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant OS

Integration causing the issue

ThermoPro

Link to integration documentation on our website

https://www.home-assistant.io/integrations/thermopro/

Diagnostics information

No response

Example YAML snippet

No response

Anything in the logs that might be useful for us?

No response

Additional information

No response

[home-assistant[bot]]

Hey there @bdraco, @h3ss, mind taking a look at this issue as it has been labeled with an integration (thermopro) you are listed as a code owner for? Thanks!

Code owner commands

Code owners of `thermopro` can trigger bot actions by commenting: - `@home-assistant close` Closes the issue. - `@home-assistant rename Awesome new title` Renames the issue. - `@home-assistant reopen` Reopen the issue. - `@home-assistant unassign thermopro` Removes the current integration label and assignees on the issue, add the integration domain after the command. - `@home-assistant add-label needs-more-information` Add a label (needs-more-information, problem in dependency, problem in custom component) to the issue. - `@home-assistant remove-label needs-more-information` Remove a label (needs-more-information, problem in dependency, problem in custom component) on the issue.

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[HairmannS]

Same here on a TP357S, always reporting 50%

[coaxx77]

Same here

[pawsnizzy]

My TP393S also only shows 50% battery

[KevinGrea]

Going by the code in this commit https://github.com/Bluetooth-Devices/thermopro-ble/commit/cbb8be9dfdc9b686ed94ad083d58785eb1805ed1 the device only reports three values 0, 1 or 2, which the integration maps to 1%, 50% or 100%. So perhaps the device reports a value of 1 for the majority of the life of the battery. If that is true, perhaps this is better as a "battery low" flag than a percentage. Someone want to try putting in a battery know to be low to see if the integration reports 1%

[rakerley]

I hooked a TP357S up to a bench power supply and took some data. It needed a surprisingly high 100mA current limit to start up and a massive capacitor on the battery terminals to be happy. I used the thermopro app and noted what the battery icon looked like. It was fastest to do the test by cycling the power supply for each measurement.

2V: 100% 1.6V: 100% 1.4V: 100% 1.2V: 50% 1.1V: 50% 1V: Sometimes this registers as 50%, sometimes as "low". The icon in the thermopro app went red and there is a battery icon on the device LCD!

The device is pretty touchy about battery impedance. I wonder if a NiMh would be a better match. They generally have lower impedance and a lower useful voltage. I don't have any on-hand to try. They should give a longer usable time with the "low battery" warning.

Battery status doesn't seem to be read very often by the integration. I unfortunately didn't leave it running for long enough on my workbench to see the "low" make it to Home Assistant.