It's possible to dismiss batteriser out of hand just using common sense, some basic engineering tests and calculations were needed to do that
No calculations are needed.
Just ask yourself a simple question: Why on earth would
everybody be making devices that only use 20% of the battery? (Including big clever companies like Apple according to Batteroo!)
Is battery life not a selling point? Not even in things like flashlights...?
So what's more likely:
a) All the engineers employed in every company in the world are idiots compared to the Batteroo Brothers, or
b) Batteroo is stretching the truth?
Take a good look at the "engineer's workbench" in the Batteriser video before answering. It's all freshly unwrapped and obviously staged. Don't the Batteroo Brothers have an actual lab where they developed the Batteriser and made the prototypes? Why isn't it in the video?
Another simple question is: Why can't Batteroo make a simple video which shows two devices side by side running until they die? What mental process are required to make videos any more complicated than that?
Is it because:
a) Batteroo can't afford two monkeys/flashlights, or
b) They're hiding something?
(You can send those questions to Ms. Journalist, see what she thinks)