If you place a Small Battery into a Large Shredder, you can immediately take out the Small Battery. The Shredder will continue to shred an invisible object, and continue generating scrap metal.
Holding onto the Small Battery until it has become as small as possible will net 2 Scrap.
If the Small Battery is not held onto until it has popped back into normal size, it will vanish.
Though I currently do not have a video, I recommend attempting it in-game. It was very consistent for me regardless of any alterations whatsoever.