Are Duracell batteries better than Energizer?

In my experience using AAA batteries in my insulin pump, the Energizer batteries lasted considerably longer than the equivalent Duracell (3-4 weeks vs 1-2 weeks).

Despite competing advertising claims, any battery's performance depends entirely on the way it is used. The "premium" batteries are designed to deliver consistent power for the maximum period, limited by their size, voltage, shelf life, and chemical energy storage system.

Any individual Energizer or Duracell product may outperform the other brand in any given application (e.g. toys, flashlights, medical devices, cameras). The only general criteria is that more expensive batteries tend to provide better service and reliability than less expensive batteries. The experience of the consumer should decide which battery to use, rather than a generalization by brand.

In general batteries marked 'Alkaline' are superior as these provide roughly double the energy of alternative batteries marked Zinc-chloride, Cadmium-free, Mercury-free, Heavy Duty, Super Heavy Duty etc. which are all non-alkaline.

Alkaline batteries cost about twice as much but provide at least twice the energy especially with heavy loads, and they are made to a higher standard that makes them less likely to leak.

They are both just as good, because they both have rechargeable batteries, you just need a charger for the brand of batteries you choose to buy.

The energizer z3 battery lasts the longest