I seem to have no clear choice on a new Converter/Charger, the Powermax, Progressive Dynamics, and the Iota are most popular, and have similar specifications. If any of these are made in the USA, that would be my choice. This is my first RV, and want to upgrade to the right equipment. I was thinking to leave the RV plugged in when not in use, in winter for keeping the batteries in charge, and I'll be using it as a 'Guest Cottage' in summer. Is this a good idea? I would also install a battery monitor, such as the Trimetric or Victron, to keep an eye on the battery condition. I will definitely be using the RV for 3-7 day off pedestal camping. The unit has a Onan 5500 marquis genny.