Testing the Eneloop Pro AA, I used the Ansmann Energy XC3000 battery tester. I first started by testing the initial voltage with the batteries fully charged. For NiMH batteries, this should be at least 1.2V, although these measured in at 1.36V. Of course, voltage will drop over use, but you need the right starting level to ensure their capacity can be realised. Next, I cycled the batteries 50 times, taking capacity readings every 10 cycles. From the graph, you can see that the batteries constantly exceeded the rated capacity, and there was little variance between readings.

The batteries are rated to last for 500 cycles, which isn’t terrible (the Duracell Rechargeable AA 2500mAh are designed to last for only 400 cycles – but they are cheaper), and maintain a decent 85% of their charge for a year. This makes the Eneloop Pro AA units a good choice for those who charge and store batteries, ready for action. Performance It's worth bearing in mind that alkaline non-rechargeable cells look good on paper, with around 1700-2850mAh for AA and 860-1200mAh for AAA. However, that’s not the whole story when comparing Eneloop and alkaline batteries, which we’ll come to in our ‘performance’ section. The Eneloop Pro AA have a rated capacity of 2500mAh, which puts them near top of the pile in this category of batteries. They’re designed for the most demanding of applications, such as camera flashes and radio-controlled cars. The Eneloop Pro AA are the company’s professional-level batteries, designed to deliver the greatest amount of power. In this regard, they certainly deliver; but these batteries are relatively expensive and offer a fewer number of charge cycles next to the competition. Design and Charges Next, I tested the capacity using the high-drain test (600mA +/-20%). Initially, I saw the batteries return a capacity of 2894mAh, which is considerably higher than the rated capacity.