Hi MMOLLECK,
In response to your e-mail and I thought I would post this here for you and others.
First of all, even though I wired my house addition and am a HAM, I am not an electrician and did a lot of research as to what, how, and where I was going to connect and distribute electricity within an OFF-ROAD trailer, both 12 vdc or 120 vac. I am not telling you how to wire your trailer and can only show/discuss methods I used, to help you build ideas and make decisions of your own. Things like grounding need to be studied and the use of safe electrical wiring practice is highly recommended, especially when wiring a trailer with both 120 vac and 12 vdc.
Here is what I did with my CT build...--- USAGE RATE -- Because of my low usage and rate of discharge ... I have two overhead lights that have been converted to LED (with fans when needed to ventilate the trailer) and one porch light that is LED. I will be adding two 12 vdc charge ports and two 120 vac ports in the trailer for charging the Metal Detector batteries, computer battery, and cell phones. Because of my low power draw (about 3 - 5 days of usage) and off-road use, I carry a spare (10 amp) battery charger, a 1250 watt generator, and have a Battery Tender Plus installed in circuit.
-- CIRCUIT BREAKERS -- ALL CIRCUITS COMING FROM THE BATTERY are circuit breaker protected at the battery.
-- LARGE CHARGER -- If I am camped for long periods, I can connect the larger charger directly to the battery, plug the 10 amp charger directly into the generator or shore-power, and charge the battery until it comes up.
-- IN-CIRCUIT CHARGER -- I have a
Battery Tender Plus (A trickle charger at 1.5 amps with long-term maintenance circuits) installed in shore-power input to battery circuit.
-- OVERNIGHT & LONG-TERM CHARGING -- If I have the trailer shore-outlet plugged into shore power, the Battery Tender Plus will charge the battery at the 1.5 amp rate over night or until I move the trailer. The Battery Tender Plus instructions says it will not cause an issue with a Tow Vehicle source (See note OFF-ROAD below) to the battery and therefore, can be left in-circuit during tow or when parked in-use. When the trailer is plugged into 120 vac shore-power, the Tender charges the battery at 1.5 amps and will maintain the battery if parked for long periods.
-- DOUBLE CHARGING -- The Battery Tender Plus says it cannot be back-powered, HOWEVER
I DO NOT PLUG THE TRAILER INTO SHORE POWER WHILE THE LARGE CHARGER IS CONNECTED TO THE BATTERY ... I do not like the idea of having two charge sources.
-- OFF-ROAD -- Because of the off-road use of the trailer and truck for prospecting (I often camp in remote areas near the US - Mexico border and other remote areas), I disconnected my power to trailer wire from the truck battery to preclude discharging my truck battery in the event of a short, even though I have breakers in-circuit, I do not want to be 20 miles from anything and have a dead truck battery.
So far (knock on wood), the Battery Tender Plus has worked as advertised.

There are some great posts on the T&TTT site that discuss electrical power and wiring that have helped me make decisions as to what type of wiring (I actually referenced these posts, as well as the Marine & Automotive specs for much of my wiring ... eg., stranded wiring in lieu of solid house wire) and would suggest you take a look at some of these posts.
Whoops, here is the attachment I forgot to add and again, these were posted somewhere in the T&TTT site (I believe), but cannot remember where I pulled it. It contains ideas and other's methods that you may be able to use to decide on your system.
I can only share my ideas and those of others ... Good Luck.

I hope this helps with your question ... Good luck