I am overwhelmed by the need for batteries in our house. A lot of the monkey's toys run on batteries and they get very upset when the batteries get drained. We frequently get the pitter patter of little feet running to us to tell us 'need batteries' or 'needs charge'. After a while, I realized we shouldn't keep buying 'disposable' batteries.
It's no secret that I love Costco so when I saw they had large packages of rechargeable AA and AAA batteries, I immediately put them in my cart. Since then I've bought 3 more packs. The Eneloop batteries from Costco have been wonderful. We had to buy a separate charger and based on a little research and consumer feedback, we bought this La Crosse Technology BC-700 Alpha Power Battery Charger. It's been so good to us the past year that we just bought a second one to keep charged batteries readily available.