I think it is a good idea to understand what to look for in a BW photo. You may need to look at some of the classic BW film photographs to get an idea. You don't just convert a photo into BW without knowing what would each color filter do to each color wavelength.
Your shots have only 2 tones. Dark gray and very, very dark gray. Try to avoid the "charcoal" look. And to avoid the HDR look too. The photograph should have enough tonal ranges to move your eyes around. I have seen some shots with a very balanced tonal ranges. If you divide the frame into 9 squares, each square would have the same amount of tonal difference. Those shots hurt my eyes, BTW. 