I guess that those who seemed to take offence at my thread did not notice that there was a question mark in the title. In other words, it was a question, NOT an absolute statement.
There are a large number of RV owners that a happy with the 2 batteries that came with their RV. I am. If you want more storage capacity, so be it.
I mainly boondock. We use our motorhome about 4 months per year. I have a 5500W generator and solar panels. I have 2 golf cart batteries from Costco. My batteries are usually fully charged by end of day. Faster charging would be nice but you have to have to capacity to do that. Next time I replace them, I'll be buying golf cart batteries. When the price of lithium comes down, I'll reconsider. My thoughts:
1. Little maintenance, I check water level every couple of months but almost never have to add water. I don't use any protective equipment other than gloves and glasses. I'm not splashing acid and they are several of feet from my face. I am near sighted so always have glasses on. Safety glasses are a must whenever working on almost anything.
2. I almost never run the batteries under 1/2 charge.
3. My class A came with golf cart batteries and a smart charger that never over charges. My solar panel also do not over charge.
4. NO battery should be drained completely dead. Lithium's life will be shortened by doing so (although not a severely as lead acid). Therefore, comparing cost in AH by using full capacity of lithium to 1/2 of lead acid is not valid.
5. To replace 2 golf cart batteries with lithium, 2 lithium should be purchased. The lithium will have more usable capacity but, if you don't need the extra capacity, it's a moot point.
6. Two golf cart batteries from Costco total $240. Some pay much more but I don't see a need to. Two lithium cost between $732 and $1598. That means that to replace 2 lead acid golf cart batteries that already meet your needs with lithium would cost between 3 and 6.7 time more. Plus the charging systems may have to upgraded at substantial cost. For example, the engine driven alternator regulator, the solar regulator and the charger that came with the RV. What is the cost of a new battery maintenance system system? Check before installing lithium.
7. Almost no one will built a lithium bank from individual cells. Those that have and are happy with the results well done!
8. If I want toast or need the microwave oven, I have a 5500 Watt generator. That's what it's for. I usually never run the generator for more than 20 minutes a day. Some days not at all.
9. Are most that are considering lithium just looking to replace their current 2 batteries? Do they believe that one 100AH lithium is equivalent to 2 golf cart batteries for capacity and that they will get 25 years out of the lithium? They will get more usable capacity but see points 5, 6 and 10. Maybe it is worth it if you only have room for 2 batteries and need more capacity.
10. Lithium lasts longed, but how long will you own the RV? I doubt many will take the batteries with them when they sell.
11. Weight. If you have a class C or A RV or a larger TT or 5th, you are pulling 10,000 to 30,000 pounds around. Will the saving a 50, 100 or even 200 pounds matter? Sometime a good crap in an outhouse will save more weight.
12. Voltage drop. Never bothered me. The inverter works just fine.
13. I watch movies when I want and do the other things that one does when boon docking. Maybe I'm just energy efficient.
14. If you are building a very large capacity battery bank, lithium is worth looking at. But sellers and other advocates that wave the lithium flag say "lithium is lower cost in the long run" and then talk about 100% capacity and a 25 year life. My thought is that they are not worth it for those that are happy with their current lead acid batteries. Just because I have an expensive RV doesn't mean that I don't consider value.