Will a regular 120V household plug in recharge the RV battery on the Sportsmobile, or should I plug into the heavy duty 240V plug.
Also, at campgrounds they give you a choice - what's best?
Depending on RV park power panel and your power needs, you'll have a standard 120V outlet that you can plug a properly rated extension cord into, or you can use a 30A RV service to 15A plug adapter (frequently call a dogbone).
SMB-less as of 02/04/2012. Our savings account is richer, but our adventures are poorer.
The main issue is not to run too high of amperage. That can happen with 120 or 240 volt applications. But as Herb has pointed out, using a small dogbone adapter is fine provided you don't exceed the manufacture limits. For instance, running a 120 15A dogbone adapter to run a 20 amp 120V space heater is a very poor move. On the other hand using a dogbone (often called a pigtail) rated at 15 amps to just charge the batteries should be fine. Most chargers pull well below 15 amps.
2006 Ford 6.0PSD EB-50/E-PH SMB 4X4 Rock Crawler Trailer