We use batteries for almost all our portable devices these days and it's important to know that we are getting our money's worth. It wasn't until recently that I came to the realization that Duracell doe in fact not last longer than any other battery. You may be thinking that's a pretty bold claim but I have evidence to back it up. For Physics this year we had to conduct an experiment in to which battery actually lasts the longest and so I took Duracell and Energizer and put them in flashlights to see which flashlight burnt out first and surprisingly it was Duracell. Now that I have indeed substantiated my claims we can move on to the actual Duracell AA battery pack. The 4 cells contained inside the pack are reasonable for satisfying most portable appliances. We mainly use them for TV remotes and wall clocks and the batteries don't give up on us very quickly however If longevity is important to you then I recommend you buy Energizer because quite frankly Energizer just lasts longer.