You might look to see if the CASIO keyboard lineup still has some battery powered stuff available. I used to have an 88-key CASIO that was very light in weight and could be powered by internal D cells or optional wallwart. Don't know if they have any 49-key units like that, though, but don't let the brand name throw you off, CASIO makes some nice stuff now and again.

Today I have a little M-Audio 49e controller that I use when traveling, it can take its power from the USB hookup and since I always also have a laptop with me, not a problem for both power and also using softsynths with it since it has no sounds. It is also dynamite when jacked into m Ketron SD4 for the sounds, but I don't have a way to provide battery power, although I could rig up an external battpack to provide 5 or 6 volts to the things if necessary.


--Mac