I am converting a gasser to electric. Does the CG stay the same? As right on the spar , since the is no fuel to burn off.

i use velcrow and wire
i put small hole right behind propshaft in the fuse then i hag and slide the batt up or down the fuse until it hangs at the CG i want ...keep in mind this if what i do for the foamie so not sure how easy it will be for balsa to make hole and hang entire plane
might be to heavy and wire rip through the balsa huh

Um.ok...

Yes the CG would remain the same... don't forget, you check the CG on a glow plane with an empty tank....