Interesting idea. Don't really see the purpose, though...

I mean, if things on this planet ever get so bad that I can't buy batteries for a portable radio, then I doubt there will be any radio stations to listen to, either...

I suppose if one traveled to places where batteries were not easily purchased, such as the middle of the jungle or something, it might be useful. But not for folks like us who get the DT's when we're away from our net connections for more than a weekend...