I built my own for about $30 worth of parts but you can spend more and get one already built with molded ends. Not sure if you can find it cheaper but for reference, Amazon has a couple starting at $89 that I could find.Linus wrote: ↑Tue Oct 15, 2019 1:36 pmYour 5th wheel most likely connect to a Nema 14-50 plug. Depending where your trailer is setup (campground, friends field, etc.) do you have access to 220-240V?
If you do have a decent supply, I would buy a dumb level 2 charger like a Duosida or similar. When you get home unplug the trailer (run on battery) and plug the car in for a couple of hours, this will do the bulk of the charging. Then plug the trailer in and use your level 1 charger to top up over night.
Even better would be to make a plug splitter so you can run both at the same time, the 5er will only have a significant draw when you are running the air conditioning or if you cook with electric.
https://www.amazon.com/RV-Female-Lighte ... 934&sr=8-6
As you said you're probably never using close to 50a, either get a EVSE that allows you to set the maximum current(such as some Juicebox's) or a cheap 16a Duosida like you said. I can't see the RV would ever draw enough current as to need the extra 16a drawn by the Duosida