Hello.
Now I think about a way of not having any switch:
karlok:
And if I have an always current flowing though the voltage divider and the analog input, what do you think, how much current is drawn?
Additionally, I am interested in the way of how to calculate the current drawn and the estimated life using what the battery says about its mAh ...
So, assumingR3=10K,R4=1K. Higher resistor values decrease the current drawn, AFAIK.
Battery full = 9V, i.e. 9V*1K/(10K+1K)=9V/11 =0.8V (analogRead = 164)
But how to calculate the current drawn ??
For calculation assume capacity Q=2000mAh, and current drawn: I = 50mA, then I think time: t=Q/I=2000mAh/50mA=40h (that would be bad, it is not even two days)
( I had an idea with a relay. )