It comes up when plugged in, for values of "comes up" that include "hello, I don't know what time it is, please help me." So it sounds like I could bring it. cattitude doubts that the batteries are cross-compatible from one brand/manufacturer to another.

My thought is that the 386 comes first, in part because it's lighter; the 486 with battery problems if we're both there at Easter, or on a future trip if not.