Monster Cable Products (perhaps you have their speaker wire), also sells alkaline batteries.  The packaging for the batteries claims that they last 25% longer than standard alkaline batteries.  Energizer, which, with Duracell and Rayovac, provides 95% of the standard alkaline batteries sold in the U.S.,  took umbrage at the clam and hired an independent lab to test, and it found that Monster batteries lasts 9% less than those of Energizer.  Here is the false advertising complaint via

Stickler point:  Energizer alleges that even Monster’s own packaging is an admission of falsity.  The packaging shows a bar graph comparing MONSTER batteries which last 230 hours, to Brand A, which lasts 170 hours, and to Brand B, which lasts 190 hours.  Energizer alleges that 230 is 18% more than 190, not the claimed 25%.  That may be, but I’m of the view that 230 is 21% more than 190.