One problem related to battery has been reported for the 2005 Ford E-450. The most recently reported issues are listed below.
I bought a new 2005 winnebago motor home on a Ford e-series chassis and the battery goes totally dead after sitting for two or three weeks. The dealer and Ford tells me this is normal, yet I have had 5 other motor homes on Ford chassis and left them out all winter and the batteries were still charged in the spring. This problem still exists and no where in the Ford literature or winnebago literature does it mention this. A motorhome is not a vehicle that you drive every day and this could end up leaving you stranded in the mountains. This has happened numerous times.