[Al Skierkiewicz]

Alan,
While it might add a slight series resistance, the teeth of the star washer bite through any surface crud and oxidation on the lead battery terminal and when tight produce more contact surface than the terminal. AS the hardware tightens on the normal terminal it deforms and produces a cup shape. The ability to keep the terminals from moving is the distinct improvement here. We have batteries labeled as far back 2006 that we use for practice that have no issues with loose terminals.