You'd only need about one or two black batteries for this. Is there a specific design idea you have in mind? Seems like you're going for a popup/hammer bot hybrid.
Anyway, to start you'll want to switch the wheels out for shiny hubs, and try to swap the hammers out for razors. You' will only need two DDTs for that setup, try to use extenders to get as many razors on the arms as possible.