Presumably you have checked stuff like trunk lights, underhood lights and any stuff like those things that an Accord has. A trunk light that doesn't turn off will do it in 3 or 4 days.
The dealer should have done a power drain test. A modern car will always drain at a rate of a few milliamps to keep enough of the computers, anti theft stuff and the remote key "listener" alive and that number should be known to the dealer. Much more than that ( whatever it is) merits a proper diagnosis.