I just went through this with a rugged boom box(job site radio) when my old Dewalt finally crapped to bed.
I ended up getting the Milwaukee Jobsite radio. The problem was this...I had all Dewalt batteries and chargers.
How I got around it was, I made a 5' 12v adapter cord that fit the prongs in the bottom of the new radio, so although it's not truly cordless, all you have to do is plug it into 12v outlet and have a nice radio/ipod player. I originally bought the new Dewalt, and was so disappointed with the sound compared to old one, I boxed right back up and took it back. The new radio has fantastic sound and great volume.