Do Duracell batteries last longer than Panasonic batteries?

The main reason one battery will last longer than another is simply a matter of materials used in the construction, and the chemicals used in the electrolyte. For instance, you have carbon batteries, lithium batteries, metal hydride, Mercury, lead-acid and who knows what else out there on the market, and some will lend themselves better to one application over another. Also it has a carbonhydrate that makes it last longer.

At the same time, I wouldn't believe everything you see and hear in the TV commercials, either. The application for which the battery is being used also plays an important factor, as well as the manufacturing processes. It's been my experience that sometimes, the lesser expensive battery will provide the best performance in the long run. The only thing you can do is experiment a bit to see which is best for your particular application.