.
.
The only way to tell if a battery is discharged, half charged, or fully charged is to check the specific gravity of the acid in each cell- - - -something 90-something percent of the people reading this post will never do.
Jerry
I'd bet 95+% will never do - and never miss doing.
My old trucks' batteries are sealed, Absorbed Glass Mat (AGM) batteries. Even if there is a way to measure specific gravity, who cares.
