Electrical power : what difference between Lithium 18650 3,7V and 3,7V electricity from the mains (via a transformer used for mobile phones)

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1

Hello.
I'm using a TTGO Lora board and I would like to connect it to a socket on the electrical network. To connect to the socket, I'm using a AC-DC adaptator 3,7V 100mA. I have also tested another one that is 3V 355mA.

I have connected the socket to the following pins of the board : 3V, and GRND.
It doesn't work. Meaning : the board doesn't start (no display on the OLED screen).

When I'm using a Lithium battery 18650 to the 3V and GRND, it works.

What is the difference between a Lithium battery an the electrical network ?
I don't understand why it works for the lithium battery and not the electrical network.

For information : I have tested to connect the board to the electrical network via the USB interface and it works.

I have also tested to connect the C-DC adaptator to the "white plug of the board with the red and black cables", and same result : it doesn't work with the electrical network.

Thans for your explanation.
Regards.
CH

2

What is the measured output voltage of the 18650 ?

3

You should ONLY connect a battery to the battery connector (white plug). Connecting a power supply may damage the board.

To power the board from the mains, use a 5V 1A adaptor and connect it to the 5V pin.

4

Plug it in to a 5V USB mains adapter.

5

Hello.
That's work fine with a 5V adaptator connected to the 5V of the board (+ GRND of course).
Thanks a lot.

6

You are welcome
Have a nice day!

8

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