Battery life 2020 Jayco Precept 34g

I Wonder if the agms could service the 12v and dedicate the 2 lithium to the frige and tv.

With an adequate solar system, batteries, panels and controller, could be unlimited. Dry camping with an electric fridge can be done but may not have been the best choice for you. I recommend you not throw anything at this problem. Get a plan based on calculations so it works. No you can’t build from there unless the wiring and controller are adequate.

Well I figure I'll start with 2 battleborn lithium (200 ah and 2 24v 200w panels and x fingers. I can always build from there.

I just hate throwing out 2 6v agms.

You will have to do a multiday test. There is NO standard or rule. The ONLY rule the OEM's will state is, 24 hours. After that they do not gurantee anything. Funny thing is, on Jayco towables, they state to use 27 series 12 volt batteries. Whether 1-2-4 or 6. 6 on the large 5th wheels with residential. Your Jayco is not designed for boondocking more than 24 hours. Doug

Our 2015 Winne has a gas fridge so cannot speak from experience. Had we gotten the same coach with a residential, it would have come from the factory with 4 batteries (gas fridge coaches came with two). I think that would be prudent for you to consider, also.