Single-Use Batteries are used - if ever - extremely early in the game when you have almost no resources to produce EU through a generator. Now while coal and redstone can be found easily, you usually have a definite lack of rubber at the start of the game. Changing the recipe to take uninsulated copper cable would make it more useful at the start of the game.
In addition it might probably make sense as well to use coal instead of coal dust, as usually by the time you have a macerator you usually have a way of generating power through a generator, rendering the single-use battery useless. Besides: it effectively removes 625 EU from the 5000 EU these batteries generate as you have to power the macerator.