So indeed, it should stay plugged, which has also been my experience.
Someone handed me the node saying it was dead, and if perhaps I could revive it. I spent a lot of time trying various things, playing with the jumpers, etc. pressing reset button, trying different baud rates, both under windows and linux, until I finally decided to give it a try to cut the battery connection and wire in a fresh battery, and that was it.
as bertrik recommended the battery should be plugged for configuring the node, and the sentences in manual paper regarding damage and unplugging the battery had made confusion for me.
The manual has some truth to it, but as I said, the battery charging chip really wouldn’t be able to do that much to a non-rechargeable, but safety first.
As you can see from the schematic diagram here, the charging chip (U4) is not populated. If I haven’t overlooked something, there is no electical connection between the USB power supply voltage and the battery. The USB connection only supplies the USB UART chip, whereas the battery supplies the rest of the device. However, the various kinds of supplied documentation are pretty inconsistent, leading to confusion.
The biggest issue by far with the sensor is that it doesn’t work, and the manufacturer lists wrong specifications. The claimed IAQ output is missing.
