I suggest that you connect your meter leads to the battery cables and watch the voltage as you drive either direction.
More than a 20% decrease in voltage when a motor is energized indicates a seriously depleted battery.
I'll also suggest that you take a look at the water levels for each cell.
Lots of people ignore battery maintenance.
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.