[Feature request] Show battery only if <20%

[AleXSR700]

Hi, I could have sworn this used to be normal behavior, but would it be possible to add the option to show battery level on the screen if it drops below a certain value (e.g. 20 % or 25 %)?

The information is not needed as long as battery is full, but once it heads towards a certain level, BLE will stop working. Being able to see low battery warning would be great.

Thank you Alex

[pvvx]

measured_data.battery_level <= 5

[AleXSR700]

measured_data.battery_level <= 5

Is this <= 5%? If so, I think the threshold is too small as bluetooth will stop working long before that.

[pvvx]

It works for me at 0% for about another month.

[AleXSR700]

Including bluetooth?

I will "reboot" the device by removing the battery and see if the ble broadcasts again.

[pvvx]

[AleXSR700]

? Your charts only go to ~20% battery level, not 0%. What were you trying to show me? :)

[pvvx]

At lower temperatures the battery percentage will be lower. And so on until zero. The thermometer will then turn off. Will wait for the warmth. The battery will heat up and the thermometer will turn on.

[AleXSR700]

But the issue is not the temperature. I was/am talking room temperature.

At room temperature the ble will not work at 0% battery. It will probably stop working somewhere between 0-20 % battery level. So it would be a nice feature if the battery percentage would start showing once the battery level drops below x %. That way the user can see that ble stopped working due to low battery.

[pvvx]

I have many thermometers. And they all work at 0% battery for quite a long time.

[pvvx]

At room temperature the ble will no work at 0% battery.

Usually at 0% battery and +25C it still works for about a week.

Do you want the program to analyze temperature, battery quality, the presence of a capacitor in the power supply and other parameters?

[AleXSR700]

I am not sure that is the case when the battery is discharged at room temperature. But I will monitor and report back.

[pvvx]

0% battery = 2.2V. The chip operates up to 1.8V. Software limited to 2.0 V.

Option with CR2016:

[pvvx]

I am not sure that is the case when the battery is discharged at room temperature. But I will monitor and report back.

If a capacitor is not soldered into the thermometer, then some batteries will work up to 20% and immediately turn off. Loss of battery charge in the absence of a capacitor recommended by the manufacturers in the power supply is up to 40%.

When there is a pulse load during transmission, the battery voltage drops and the thermometer turns off.

[AleXSR700]

Interesting. Any way of checking without breaking?

Mine, according to my data, dropped quite suddenly from 8% to 2%, stopped working and is showing:

Is that number supposed to represent something, like e.g. mV?

[pvvx]

This is the voltage in mV. The recorded value is below 2.0 V, at which the thermometer goes into sleep mode for a few minutes.

[edmundo096]

The info on the last comments are actually interesting features of the CFW.

Not sure if those "facts" are commented on the main README but they are quite nice:

Usually at 0% battery and +25C it still works for about a week.

0% battery = 2.2V. The chip operates up to 1.8V. Software limited to 2.0 V.

If a capacitor is not soldered into the thermometer, then some batteries will work up to 20% and immediately turn off. Loss of battery charge in the absence of a capacitor recommended by the manufacturers in the power supply is up to 40%. When there is a pulse load during transmission, the battery voltage drops and the thermometer turns off.

The recorded value is below 2.0 V, at which the thermometer goes into sleep mode for a few minutes. ...and LCD shows the mV.