This is such an obvious experiment that anybody with a working brain can think of it. It's also an experiment that bloggers will love to do.
Within a week or two of shipping, there will be a huge database of products with before/after testing.
It needs to be done right though.
The real test is not so much with and without batteriser, it's without batteriser, and then how much extra time the product gets with the Batteriser on those "dead" batteries.
This is the when their whole 800% BS will come crashing down. It'll be a few 10's of percent at best with most products, with many (majority?) in the single digit percentage if not negative.
And that's if the product even works reliably and fits, which they have had problems on the prototype units with.