Ni-MH batteries are pretty straight forward items these days. Performance seems to vary from one battery to the next no matter what you buy. But I have had pretty good results with Eneloop. These are the pre-charged 2550 mAh Eneloop Pro (K-KJ17KHCA4A) and were in fact charged for use right out of the package. I bought them on clearance so I'm guessing they had been on the shelf for a while. All four had a very usable charge but not a complete charge. Packaging claims they will hold 85% of the charge for one year. I 'd say they had at least that. Battery chargers have their variations too. This one, model BQ-CC17 in case you see it sold separately, has two features I find helpful: 1- the AC plug folds up into the unit when not in use making it less likely to poke other things during storage or travel. 2- it can charge any number of batteries (1-4). Some chargers require charging to be done in pairs. Otherwise it's a simple charger that accepts AA and AAA and does a good job of keeping batteries from being put in the wrong way.

It come with 4 AA batteries but it also charges AAA batteries with no additional adapter. You just have to order AAA batteries separately. Hope it will last for 500 charges as advertised.

I bought these batteries and the charger for my controller for my gaming system. Reviews for the rechargeable batteries made for my system only have fair reviews. These have excellent reviews. So far, they are great! Last a long time and re-charge quickly. Hope to get many years of service from this set and save money.

The design is as compact as it could be. It doesn't even require a power cord, so there isn't anything to get entangled, get lost, or just look ugly. Just the minimalist unit, ready to perform. I recently got that AC/DC portable radio that uses AA batteries. AA and AAA size is what my gizmos use. This charger accommodates batteries of either size—up to four at a time, in any combination—and lets you know when it is done charging each by turning off the LED associated with the slot. As for the included batteries, they do seem to have a long life. They perform so well in that portable radio of mine, I figured: Never mind the power cord, I'll just keep playing it on battery power. It wasn't until several weeks later that the sound and reception quality seemed to tell me it was time to recharge. This charger pretty much eliminates any hassle that may come with managing the rechargeable AA/AAA batteries in your home!

I use these constantly around my house, they charge quickly and always provide the juice I need. No more tossing batteries in the trash or running to the store.