Battery condition chart ( resting voltage ) Source: Internet site......?

I know the author of "The 12-volt side of life" uses this in his article. Good read.

http://www.marxrv.com/12volt/12volt.htm

I disagree with his picture of 12 volt batteries, where both positive and negative are connected to the same first battery.

Positive on battery #1 , and negative on battery #4 is a more balanced approach to draw on gone cells.