Adjusting Battery Charger

I discovered that a lot of people have had trouble with the BE 500 charger not turning off with the result that the batteries got fried.
Mine wouldn't turn off either. I know nothing about electronics but took the cover off the charger to take a look. I discovered two little phillips screw heads. I thought they must adjust something. I fiddled with them and discovered that by turning one of them slightly, I could get the charger to shut off. Maybe an answer.</>