Re: [A/S] Argosy Newbie

[Jim Dunmyer <jdunmyer@xxxxxxxxxxx>]

Jim,
You're correct in both of your assumptions: 

A diode isolator will prevent the trailer battery from feeding the
starting battery. If you have a second battery in the tow vehicle, it
would be in parallel with the trailer battery, behind its isolator.

Although you will have a heavier load on the vehicle's alternator when
first starting the engine, my measurements show that the charging to the
trailer battery is so limited by the wire size that you have little to
worry about as far as overloading the alternator. If you're concerned,
let the vehicle idle for a few minutes immediately after starting, to
reduce the load.

The isolator will prevent back-feeding the vehicle's battery from the
trailer, so you needn't worry about frying the wiring. In my case, I use
a relay whose coil is powered from the ACC line, which is usually
disconnected during cranking.

Get a copy of Barre's "Managing 12 Volts" if you'd like to learn more.
Bill & Jan Moeller also have a book on RV electrical systems that's very
worthwhile, especially for their work on the 120VAC side of things.

                                      <<Jim>>