After some investigation on the forum this thread came on the radar.
there i found this part
You are measuring the output of the 3.3V regulator on the Wemos, so you get answer of 3.3V. Use the A0 pin with a 180K resistor connected to the 5V pin. The Wemos has a voltage divider on the board which allows voltages up to around 3.3V to be measured. The 180K will extend this to around 4.7V.
it seems i have a mistake in the wiring. Instead of connecting the 100k resistor directly to the battery it have to be connected on the 5v on the Wemos. For now i did some quick test and voila there where some 1024 results. So it seems the A0 is working properly.
Now doing some solder work, will keep you posted.