I soldered two wires on female USB type A pins,one wire to ground and the other to the VCC pin. I was trying to check the battery voltage of the li-ion battery in my flashlight,
I connected the a voltmeter to the VCC and the ground wires of the female usb-A connector. The female USB-A connector I connected to the the flashlight cable: one side has a male USB-A connector and other side has a male USB-C connector which is connected to the flashlight.
I haven't gotten any result (0000.)
I tried it on a cellular phone and I got only 0.4V,Vwhile on the phone it says 80%, so the 0.4V is probably a result for something else.
Is there any simple way to improve the connector to be able to read the voltage of the battery?