battlemode is how you can use all 4 sets of hotkeys available (hit f12 to make more appear)
When you hit enter (and have no chatbar) that's when you're in battlemode, it's essentially so that classes with enormous amounts of skills (usually magic casters, although you can use it for armor swaps, or healing items, or items period).
Hopefully that's what you meant, but you can set your bars in the same place you set your shortcut settings.