Empress Band

This costs 1kCP and can be recharged once a week (or repurchased once a week).

In other words, you can use this 7 times each week, at 16 hour intervals.
For the next 180 minutes, or until you get 1000 extra exp with the effect - whichever comes first, you will get 50% more exp each time you get exp for defeating a monster.
It has no effect on ENMs nor on scrolls.

I think this one is clearly better than the chariot band, since the total free exp is potentially double. In any real exp party you'll get the 1k extra really fast. Even solo you'll get it long before 2 hours is up.
The exception might be if you're soloing at higher levels for 20 exp per kill… but really, who does that?