[JRTJH]

For most people, it would wind up being the same as the "green leaf ECO monitor" on Ford's "hybrid cars"... A novelty to use at first that quickly becomes "something else to ignore or that breaks and needs fixing"....

If you really want "that information" get a voltage meter and wire it inline with the converter output. An ammeter, unless you significantly change the trailer wiring, wouldn't help since the charge amperage to the battery is "what's left over after user demand is met (in other words, the battery gets the amperage left after all the lights, furnace, water pump, stereo, refrigerator and water heater demands <controlled by the user> are powered).... So, to know "what's going to the battery" you'd have to know "what's being used before the battery".. That kind of monitoring wouldn't come from a simple ammeter on the converter output...

I find that if the trailer is "relatively quiet" I can tell the charge status of the battery by considering what all is "turned on in the trailer" and how fast the converter fan is turning. If no lights are on and the fan is turning fast, the battery is charging. If a few lights are on and the fan is not turning, the battery is charged, or close to it.

For me, that's about the extent of my "need to know" while camping. At home, plugged into shore power, I let the "genie in the converter" do its thing......