Did you find the answer to your question? I would like to know more about how you replaced the lead acid battery with a lithium. I would like to do something similar in my trailer.
I had a 2012 pop up on the bed of a 2012 Nissian 1/2 ton. With the factory supplied converter and two 6v lead, 120 lbs. I wanted to cut down the weight, so I replaced the battery with the Battle Born 12v and a Xantrex 2000 inverter. Both fit into the battery space. I also removed the propane stove, 3way fridge, and propane tanks, saving another 380 lbs. We used an electric induction cooktop top. (Cut cooking time in half).
Didnt have to do much to the electrics in the camper, other than disconnecting the original converter and wire the battery to the inverter. Installed a couple of disconnects and it worked great. Was able to boondock for a couple of days.
I am a diy guy so i did this my self, with the help of you tube and these forums. (Thanks for the help members)