Hi @PJ_Glasso thanks for the reply.
I didn’t fully understand … are you saying I can’t supply 5V power to the board on that 5V pin AND have a battery soldered on the board at the same time? E.g similar to how it works when most devices are powered by USB connector. 
The wiki saying a diode end towards the battery did asume external power source is a battery, I found that exact same question and answer on an Adafruit forum regarding a different board 
So I need a diode on the line entering the 5V pin.
I will search this forum too, I thought at this point I was close to clarifying my questions here 