i think i have the battery you are gonna buy:
Emerging Power EP-DVD-NM4500 9.6V 4,500mAh Rechargeable NiMH Battery Pack
if this is the one, it comes with a cable with multiple tips, each a different shape and size, none of which will work for the UA-5. the oade's made their own cord to connect the two, and i am not sure of the diamaters/shapes of each end. i do have a broken one though, PM me and i can send it to you. either you can fix that one and use it or take it to radio shack and they can most likely create a new one for you with the same connections. fwiw, you can find these batteries online now for about 80 bucks and i *think* they last for about 6 hours. i like mine.