I base my suggestions on the following book by Harold Barre. It's called "Managing 12 Volts: How to Upgrade, operate and Troubleshoot 12 Volt
Electrical Sysytems". I highly recommend it.
I have a new Magnatek 7300 automatic switch mode (3 phase) converter/charger in my 2004 CCD. I assume that a 2003 Bambi may have a similar system.
It works great and charges my 212 AH Deep Cycle Scrubber battery in about 2 hours from 50% to 80% State of Charge while we're "Boondocking". I sized this battery based on the recommendations in the book. I minimize DC usage (lights, fans, TV, water pump, etc.) while charging with the generator to allow the battery to accept all/most of the 55 Amp DC charging current.
I use a Honda EU-3000is to charge. This gives me about 23.3 available AC Amps of which my converter/charger only needs about 10-13 Amps to convert to the 55 DC Amps. I have extra AC to use for TV or some other small AC appliance.