Hi Bob! Welcome, you're new here aren't you
Welcome...
Based on your profile you have a 2005 correct? How old is your battery? How long does it take to discharge? Whats turned on? Do you have a Television perhaps, or things plugged in - like phone chargers?
One thing to try -- charge the battery --- then disconnect it --- there is a red switch you can disconnect the battety through. Does it discharge while it is disconnected?