Converter vs. Charger, Whats in a name?

Thanks, Jumper, for putting this out there, and thanks, Mod, for breaking it into paragraphs. One question for the group. I purchased a Sears 'intelligent' charger for a dry camping trip to Yellowstone. My thought was to use the 'fast charging' feature of the charger in the mornings to bring my battery up to full charge more quickly than would have been done with the on board converter. Just to make sure that I didn't upset anything in the on board 12VDC system, my practice was to isolate the battery (group 31) via the battery disconnect switch, and then attach the Sears charger directly to the battery. This brought the battery up to full charge in much less than an hour. Downside, of course, was that I had no internal 12 volt electric during this window. Question for the smart folks... Was this a prudent thing to do (isolating the battery), or not necessary?