Well, all depended on what type of AC and trailer. I ran my Goldstar AC came with a 2012 Aliner Classic just fine with a Yamaha 1000W. I did not buy the generator for the AC, but I was surprise it ran fine in the summer.
I installed an AGM battery on my Scout for reliability. When I retired a couple of months ago, at work we had a 24 volt walk behind forklift that was used for something at least every other day. I installed four AGM batteries in it over 10 years ago. Batteries were wired 2 in a series and those 2 series were then wired in parallel. They are still going strong.
I agree that agm batteries are better and longer lasting, IF they are recharged correctly. I had this issue with dual Odyssey Batteries in my truck. They need a higher charging voltage, which the current Aliner charger may not be able to provide.
Lithium Iron Phosphate (LiFePO4) batteries are peaking my interest; in particular, the 100 Ah Battle Born battery. Here is an article that explains the advantages of this type of battery: https://www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/
