This is an excellent and simple tech write up about how ISO works with sensors and batteries.
Many years ago, Lee Trevino (pro golfer) said that all golfers should play at least one round of golf with only the 5 iron... so that he/she will learn what can be done with a club. I tried it and was a much better golfer after I did.
I think the same is true for cameras. We should learn and experiment with the camera controls so that we know what we can do with what control and how that control affects other aspects of the IQ and camera capability. Short periods of experimentation and understanding how the camera does its stuff can make us better photographers.
Thanks for the post.
Dan (Nikon D800,V2,Sony HX400V,Lumix ZS40) "I don't read, I just look at pictures" - Andy Warhol