I followed this tutorial:
But Im using a 3.7V battery that im measuring which the meter clocked at 3.17V. Im using 2 of those same batteries in series (7.4V) as the source that goes into the 7805 regulator.
But when I connect the 3.7V battery (3.17V charged), all 4 LEDs light up instead of just the 1st one which should according to the math.
I uploaded the circuit but i think it'll be quite hard to follow:
This is what the diagram should be: