[75vs1885]

I agree with what has been said but like to add that its beneficial to mount the charger on top or on the sides of the charging station. Also, make sure you know how much space you have in your pit.
On the team i'm on, 1885, we have a shelf-like design, with a charger that can charge 6 batteries mounted on top, with two additional single chargers on the side. we also have wheels on it. Larger wheels are better because when transporting in and out of arenas its likely that you'll encounter "tough terrain" (meaning lots of bumps and potholes). Don't forget to make it look nice! put a couple coats of your teams colored paint on it.
Hope this helps and send pics when it's done!