Adding the following in parentheses (sp?) edit to main post:
(I would reccomend a time per battle of somewhere between 10 and 25 minutes.
The number you use should include waiting time and the actual time spent in battle itself.
Please reset that statistic to 20 minutes when you are done using it, as all changes are left until someone else changes it)
Of note, my experience has been that waiting until the end of a battle (if you are going to win) is beneficial in terms of the amount of experience recieved. However, if you are going to lose, it might be best to just leave and join the next room.