Race AA batteries through tubes made of copper wire

As a method of testing battery output, it seems a bit elaborate, but racing AAs down coiled copper tubes looks like a lot of fun. Mr. Michal:

Duracell, Varta or Energizer, Which Will Be the Best? In this video you'll see two races between aa batteries. Infinite loop and DRAG RACE. How to make the simplest electromagnetic train in the world ? It's very easy. You only need these three parts. 1. copper wire raw 2. battery ( AAA, AA or C ) 3. and two neodymium magnets ( it must be larger in diameter than battery )

I figure as a benchmark, you'd need to immobilize the tube for comparisons to be fair? Say, if you wanted to create a whole YouTube channel dedicated exclusively to well-controlled battery races.