I have a New Idea 150 and check the battery acid with a hydrometer. When the tractor has been sitting all week (I mow on weekends) the battery acid is clear. If I check the battery acid just after mowing the battery acid is a dark gray (almost Black) in 2 of the 18 cells. I think the movement of the tractor shakes up the acid and sediment. What is the black stuff? Does it do any harm? Should I flush out the acid and replace it with new? Any help you can give is greatly appreciated. Thanks |