i have a quite new t-echo running on meshtastic 2.06.9
other than my Rak Devices or T-beams it is showing voltages near 5V when charging.
i Checked the Specs, and those show a 3,7V Lipo Battery.
is my T-echo dramatically overcharging its Battery ? Dangerous?
or is it just some Bug/Artefakt ???
thank you
To clarify, are you measuring that voltage at the cell’s terminals? No LiPo cell should ever be charging above 4.35Vdc with most systems limiting to a max of 4.2Vdc.
no , i am just reading what the t-echo is showing on its e-ink display , and also what it is showing in the android app… it goes up to, 4,77 V when charging.
i did not open the t-echo yet, to measure the actual voltage of the battery wehen charging
I think there is just as much chance of the voltage display being inaccurate as the charger providing an over voltage. The only way to really be sure is to put your meter on VDC and check across the cell terminals.
I opened the device while charging (USB 5,13V 550mA) after almost empty.
the voltage reading on display and in the android app is showing 4,6V
the voltage i measure at battery connectors is 3,7V !
so,this does not seem to be a problem.
Most of the boards have a autonomous hardware charge controller that can not talk directly to the MCU (the T-Beam being the notable exception) so the MCU has an analogue probe pin to measure the voltage. Designs vary from Board to Board, but this is not very reliable and the firmware has to guess the charge state from the applied voltage. (e.g. there’s no signal 'i am charging now, i am no USB now, i am on Battery now) Chances are good this pin is detecting the voltage from the connected USB cable and not the charge voltage.