Can you use any 18v fuel battery with any 18V fuel tool? I see tools (kits) with 1.5a/h batteries and others with up to 5.0a/h. Looking at getting a drill/driver and possibly a fairly heavy duty impact. The impact's come with larger batteries, but can those larger batteries be used on a drill that came with a 1.5a/h battery (and vice versa if you are in a pinch)?