Pros: Since making the switch to Ni-MH battery technology over 8 years ago we now have more than 100 of the AAA and AA each. We use them everywhere and they have a long shelf life.

Cons: None

Pros: I have been using Eneloop batteries for a little over three years now, and have only had one go bad on me. They work better then any battery I have ever used (rechargeable and non) and have long charge life.

Cons: You need to buy a decent charger if you want to get maximum life from these guys, which means more money on the front end.

Other Thoughts: I have a child, so I also have about 40 things in my house that run on batteries. Buying rechargeables has saved me a lot of money, and they are not much more expensive than non-rechargeables.

Pros: I’ve purchased several dozen of the Sanyo Eneloop AA and AAA batteries over the past few years. They will seemingly last forever if you use a good charger such as the POWEREX MH-C9000. Any charger used needs to have a microprocessor that can read the battery and keep from overcharging. Cheap chargers can permanently kill the batteries within a few charges. When new, before first use, I run a break-in charge that takes about 48 hours. When needing a recharge I run a regular charge but select a low 300ma charge rate which takes about 6-8 hours. If I do that, on subsequent charges, the batteries typically charge to about +5-10% of their rated capacity. After a number of charges, if they don’t exceed their ratings, I run a REFRESH/ANALYZE cycle that will bring them back over spec again. I haven’t charged any of these more than a few dozen times so I can’t say how long they will actually go. I use these batteries in everything in the house from remote controls to game console controllers to clocks and flashlights. I bought size adaptors to use AAs in size C and D applications. Remote batteries typically have lasted two years before needing recharging. The batteries have lasted in Wii controllers almost as long as alkaline batteries before needing to recharge. I keep about a dozen charged and ready to swap out as they hold up to 75% of their charge for 3 years sitting unused.

Cons: Charging times when charging them properly.

Other Thoughts: These could literally last most of one's life when properly charged. Key is to buy a quality charger. It may seem fifty bucks is a lot to spend on a charger but when you figure alkaline AAs on sale cost about 50 cents each, and two charges on these will equal one alkaline, and Sanyo says they can be charged over 2000 times, even with diminishing returns the overall savings over the years is huge with a side benefit of less old batteries ending up in landfills.