I have a CA majestic. I went down the battery rabbit hole big time.
I'm now 100% convinced I would not put anything but lithium in my rig.
Now the question to ask is what is your lifestyle with your RV? Mine is 100% boondocking rarely if ever do i go to a hookup unless at my house only to keep the fridge going. my convertor is disconnected because i have solar and dont need it anymore. not to mention the convertors ruin perfectly fine batteries unless upgraded to 3 stage charging with temp compensation.
If you are in the occasional use buy what u can afford if you are like me using the rv every weekend or more buy lithium dont look at the cost as it doesnt mean anything. They are not 1300$ battleborn starts at 949$ and is the top of the lithium food chain right now with many many others prices way below that in the used market they are cheaper then agms. The math works out in your favor each and everytime with lithium so long as you follow lithiums rules.(rules only apply to diy lithium cells) no rules apply to highend bms integrated lithium like battleborn, ruixu
never overcharge never undercharge and never charge in extreme cold 30f or below discharge can go as low as -10. they prefer to be half full or less for storage. If you spring for the BMS intergrated ones especially battleborn you worry about nothing it does it all for you. I built my own so i have it on its own special program.
As you know the majestic is super tight on space they come with one battery that doesnt do anything helpful other then to get you to the next hookup. there is no space to build a bank for 2 six volts or even add more then one group 31 which is equivalent to 100amp hours 50ah are useable. Idling with nothing on except the fridge you will blow through that in 1-2 days.
My system on my majestic (yours is more likely different) power center is under the bed. I added a invertor to power up the 110 outlets and tv so the only place to add additional batteries are under the bed. I bought 2 very expensive vmax solar agms at 300$ a pop times 2 im in those batteries almost 600$ for 250ah total 125ah useable. they charge slower and the capacity i know is on its way downhill and have only had them for 5 years. an expensive mistake but had no choice as agms were the only option other then lithium for indoor use (no toxic off gassing like lead acids)
My lithium i built was used and cheap i paid 300$ for the used cells and they are still at 80% capacity and will stay there for the next 10 years. my solar system is now actually doing something rather then dumping the power as lithium sucks up every available amp that it can get whereas the agms bulk quickly to 70-80% and basically float the rest of the day wasting the available harvest in the panels.
Lithium is 100% the ideal choice for any rv large or small. On first glance it looks ridiculous expensive but after actually using one i'd never look at a agm or lead acid ever for any rv i would own. real world experience tells me they charge faster, keep a constant voltage zero sag great for all onboard electronics, keep my back healthy if i need to take it out or put it in as it weighs 20-30lbs, i can waste as much power as i want after midday until dark, no fear of dropping below the dreaded 50% level.
3-5 years is probably the average ownership of most rv's with most getting used maybe 20-30 times in that time period. if thats u then lithium totally doesnt make any sense. nor if you are hookup rv park type.
If you are a bigtime boondocker lithium is the only choice that makes not only financial sense but comfort of enjoying your outdoor time without a care in the world about battery anxiety coupled with a solar system of course.
(sounds like a used carsalesman but its true you can't damage them like you can with regular batteries.) one time with any agm/lead acid below 50% starts tearing down capacity. it gets smaller and smaller even when doing the right thing until you are faced with shelling out another 300-600$ for another 1-2 more batteries
here is an example of affordable lithium that wont break the bank.As you can see this is smaller foot print with way more capacity then 2 monster heavy vmax group 31 70lbs a piece lead bricks. 138ah is whats useable at 80% in 300cycles which i doubt more like 90% or more at 300cycles is still around 110ah useable in a GROUP 27 unbelieveable!
Valence lithium