Originally Posted by la4photo
... I am fairly certain this is the original converter as everything else seems to be original. If I am to leave the trailer plugged to 120, do I just disconnect the battery terminals, or is there an easier way to preserve the battery.
It's not a good idea to disconnect the battery if you have an old model converter. Part of the voltage stabilization (if you can call it that) relied on the battery being a load on the 12V
output. I don't know what voltage you'll see in the system without a battery connected, but if it's constantly above 14.5V you'll shorten the life of your light bulbs. There won't be other significant damage unless you've got a sensitive 12V
It's not so much the voltage that a voltmeter reads, as much as the 120 cycle ripple--you won't see that with a voltmeter but it can be significant, several volts or more if your output capacitors are shot.