Battery value problem

[ciotlosm]

I see the battery value is calculated based on fixed values. My buttons show 100% and I'm sure that is not true. While this is a possible approach, I've checked smartthings and it seems they somehow get battery directly from zigbee messages?

https://github.com/a4refillpad/Xiaomi/blob/master/devicetypes/a4refillpad/xiaomi-zigbee-button.src/xiaomi-zigbee-button.groovy

[Koenkk]

What is the voltage of your battery? (it should report that together with the battery %)

[ciotlosm]

3015 which is correctly calculated to 100%, but that can't be. I will pair this device with my gateway and see what battery % does it report.

[ciotlosm]

Using the gateway with exact same device I get battery level 43

[Koenkk]

so it seems that the gateway calculates the percentage with a different algorithm. We have to check at what voltage a new battery starts and at which points it stops working.

[ciotlosm]

Is there no way to get inspiration from the smartthings setup? How did @kirovilya extract battery %?

[ciotlosm]

it seems xiaomi_aqara component that was reporting my value also calculates it:

    def parse_voltage(self, data):
        """Parse battery level data sent by gateway."""
        if 'voltage' not in data:
            return False
        max_volt = 3300
        min_volt = 2800
        voltage = data['voltage']
        voltage = min(voltage, max_volt)
        voltage = max(voltage, min_volt)
        percent = ((voltage - min_volt) / (max_volt - min_volt)) * 100
        self._device_state_attributes[ATTR_BATTERY_LEVEL] = round(percent, 1)
        return True

[Koenkk]

It uses a different range so that explains it. We have to do some test what the value is when we put in a new battery.

[ciotlosm]

Agree. But for transition would be nice to have it consistent. Our range is wrong anyway because we have 3000 as 100% and I already have on a used battery 3015.

I recommend we adopt the xiaomi_aqara component approach and do more math when getting a new battery.

[kirovilya]

Hello. Earlier, I considered the percentage here according to this formula:
= (battery - 2700) / 5
this means that the maximum value of voltage is taken 2700 + 500 = 3200

[ciotlosm]

I've created Koenkk/zigbee-herdsman-converters#13 to improve a bit, but we can readjust once we have more samples and details.