Batteries are like everything else in my house, the kids fight over them. At Christmas I had the brilliant idea to purchase Green rechargeable batteries for my youngest son and Pink rechargeable batteries for my oldest daughter. They are 26 months apart in age and currently the worst about fighting over stuff. I saw these batteries at Toys R Us, so when I was purchasing their MP3 players to give them for Christmas I also purchased 4 AA & 4 AAA batteries for each of them. We have other rechargeable batteries in the house that are used by everyone, but this gave them batteries of their own in a sufficient quantity to run the battery draining devices they each own. I think this was one of their absolute favorite gifts. I'm really enjoying the reduction in fights over batteries. Of course they both now want their own charger, but we have enough chargers around from previous purchases that we don't NEED anymore.