hi, i like the bp the way it is. i'm always frustrated when something dies on me at school, in the morning, and i want to use it for another 3 hours, but have to spend that 3 hours recharging it. i like the bp, where i can carry around a few cheap double A batteries in my pocket, and not worry about getting specific battery types and all this. also, further modifications would have to happen in the bp, which would take up the price. i think most people are nervous of the price already. also, having built-in batteries, they're not going to last as long in the bp as consumer ones do, so i say no to having batteries built in. thanks brandon