Jeff,
We usually send the units out fully charged but there is slight depletion during shipping which is natural. It should be ready to go within 15-20 minutes of setting it up and you can run it for 8 hours right there.
The batteries are fresh so they'll take some time to condition. They start out needing more charge before switching to float at first so it'll take 10-15 charges before you start to get really rapid refresh cycles. After that they'll recharge in less time than your listening cycle.
Enjoy

-Chris