Batteries are difficult to test for a consumer. I have seen in the past (in my own, informal, unscientific testing) that some "Pro"-labeled ones actually under-performed their "regular" counterparts. So, allow me to share with you a battery test I made between the Duracell CopperTop, Quantum, and Optimum batteries, then compare them to the Energizer Max and Ultimate Lithium. Finally, I will compare them to the rechargeable, Panasonic Eneloop Pro. This was likely my most expensive battery test I have ever undertaken, and because they are one-time-use batteries, not the most eco-friendly. I apologize for the latter! PROS - Lasted long, but surprisingly not much better than the CopperTop ones - Slider packaging holds the batteries together better, though I recommend dedicated, plastic battery holders for better and more space-efficient storage CONS - Costs more than Duracell's other lines - Not worth the extra premium for a slight increase in battery life TESTING I tested the batteries by having 3 of them each used in an Imaginarium RC train and having it go around a flat, circular track. Each time it would pass a specific point on the track, a sensor was hit to track what time it completed a loop. In the end, I had an Excel spreadsheet that showed the number of loops that were made. From there, I calculated the start time and the last time it hit the sensor. Keep in mind, however, that many factors could affect a battery's performance. Some are made better for one type of use, but would fare worse for another. Surprisingly, the Duracell CopperTop slightly outperformed the Quantum, whereas the Optimum ran longest between the three. MARKETING Duracell markets the CopperTop being less premium than the Quantum, and that in turn less than the Optimum. Visually, that can be represented as: CopperTop < Quantum < Optimum ACTUAL RESULT (with the RC train) Quantum < CopperTop < Optimum This showed that paying the extra pennies for the Quantum over the CopperTop was not worth it. The Optimum, with just a slight advantage in battery life over the CopperTop did not fare much better either. So, from a Duracell perspective, I would continue to stick with the CopperTops for best value and decent battery life. Next, I threw in some Energizers. The Max and one of my favorites, the Ultimate Lithium. - Max outperformed all 3: CopperTop, Quantum, and Optimum by about 60%. - Ultimate Lithium (which is not Alkaline, by the way), nearly DOUBLED the battery life over the CopperTop! This was not surprising to me as this line is a BEAST (with the gigantic price tag that comes with it.) Visually, the RC train result was: Quantum < CopperTop < Optimum < Max (+60%) < Ultimate Lithium (+110%) Finally, I wanted to see how the RC car would work with my favorite, rechargable batteries that I depend on for my professional photography work: Panasonic's Eneloop Pro. The Eneloop are designed to hold 70% of their charge for up to 10 years, and for wedding photography, that is an important factor as I cannot afford taking out batteries that may not be able to provide the power I need at a moment's notice. The result? They did average. Visually: Quantum < CopperTop < Optimum < Eneloop Pro < Max < Ultimate Lithium Price wise, the Eneloop Pro and Ultimate Lithium afford a VERY high premium. They are EXPENSIVE. If you asked me which batteries I recommend over the other, the answer is: it depends. Some devices work better with Alkaline or Lithium than NiMH rechargables. Alkalines provide a higher, initial voltage for more power, are cheaper, but once they hit a certain discharge threshold, they become useless very quickly with certain types of devices. With the Eneloop Pro, they provide a longer discharge life, can be used for a longer, sustained period, and of course, be recharged hundreds of times. So, what does that mean? I would like to re-iterate that I am not a professional, lab-certified, battery tester. Your own results may vary from my own, informal, unscientific testing using a RC train. For RC cars, the Duracell Alkalines are my recommendation -- specifically, the CopperTop. For photography equipment and flashlights, I go with the Eneloop Pro for the long battery life and their ability to hold their charge for a prolonged time. For critical devices that require the longest battery life, such as fire alarms, I'd go with the Ultimate Lithium. With all that said, among the CopperTop, Quantum, and Optimum line of Duracell batteries, I'd stick with the less expensive CopperTop for its better cost-to-life ratio.
