These high-capacity, AA batteries are the third generation of Eneloop technology, from Panasonic and the culmination of 8 years of development for this product line. Eneloop batteries are noted mostly for their extremely long storage life, and thanks to the most recent improvements, these will last through as many as 2100 discharging and recharging cycles. That means incredible savings, since they'll hold a charge longer than standard batteries and you can charge them many more times than the average rechargeable, too. These are a great choice for powering any high-demand devices, especially those that aren't used on a daily basis. Because they're shipped to you pre-charged, you don't even have to waste the time and energy for the first charging cycle.
The long "shelf life" of these AA cells is the result of technology that minimises the self-discharge effect in NiMH batteries. This effect can cause conventional cells to lose as much as 2% of their charge per day, if left unused. By contrast, Eneloop cells have been proven to retain up to 85% of their charge over 12 months, under the same conditions. In fact, they've been shown to hold as much as 75% of the charge after 3 years. More charging cycles and longer storage life aren't all that these batteries provide, however. They provide more efficient operation in cold temperatures – down to -10 degrees C. Memory effects have been effectively reduced so well that you can pop these into the charger anytime, even if they're not fully discharged. That makes having a spare set on hand easier than ever before. Although any "slow" NiMH charger will work, Sanyo warrants this battery line for a full year, when used with their Eneloop charger.
Along with all the money you'll save over conventional, disposable or inferior rechargeable batteries, you can feel better about using these because they're better for the environment. More reuses means less waste, longer storage life means less energy used while charging and the NiMH composition is much less harmful than NiCd, which contains cadmium. Why not help your pocketbook and the planet by using smarter technology?