Ok my standard battery post (I need to save it to documents/boiler plate
Batteries come in several differnet types
Most trailers are set up to us a SINGLE 12 volt battery Often a Group 27 or 29
These are about 100 amp hours (Less or more respective) and are usually MARINE/rv or MARINE/deep cycle meaning you can use about 25 of those amp hours (same less/more) Not your best choice. Group 31 is about 130 AH and again you can use about 1/4
Using more than that "Ages" the battery rapidly.
If you can fit them a PAIR of GC2 Golf car batteries (About the same "Footprint" as a group 24 but taller) These are 6 volt which you wire like this -6V+==-^6V+==12 volt to rev (the = is a wire) around 220 amp ours more or less depending on specific version and brand (210-230 is common) and you can use fully half. that's 4 times what a single Group 29 gives you.
Now in addition to the above the batteries come in 3 different types.
True DEEP CYCLE GC-2 Golf Car batteries are often flooded wet cell. This means you add a bit of distilled water from time to time to fill them up to 1/8" or so BELOW the bottom of the filler tube. you also need to frequently clean.> Go with monthly checking of fluid level at first. And quarterly once you find out how often to add. As they age they need more frequent watering.
Maintenance free. or Sealed Valve Regulated Lead Acid. you do not add water or anything else. Most MARINE/rv or MARINE/deep cycle are of these type. they are NOT maintenance free as you need to clean (NOTE Starting batteries not otherwise discussed are also often this type(
AGM.. A sub set of Maintence free "Absorption Glass Mat" is a "Starved electrolytic" Basicaly a moist fiberglass cloth replaces the liquid so if you have to mount 'em upside down or on end or side. No problem. These are also physically rugged and able to take serious abuse
Optima.. A sub set of AGM. spiral plates so only about 60% of the capacity of the same size flat plate battery.
Cost generally increases as you go down the list.
Finally there are some new formulations like LiFePO4 (Lithium Iron Phosphate)
Right now these are most expensive of the list but the price is in free fall. If you go with one I'd recommend either Battler Born or Bioenno power. A well designed LiFePO4 battery has a battery management (Charge controller) Built in
Bioenno (NOTE I may have flubbed the spelling) does not recommend using multiple in parallel (I have one small one) Battle Born does so if you plan on multiple go with them.
Now.. with These you can use over 90% of the battery (Like 99%) and unlike the lead acid the voltage remains near constant during discharge. They do run a bit "hotter" (Higher voltage) Battle Born has a "Deal" with Progressive dynamics to provide a converter matched to their product.
Some modern converters and inverter/chargers (I have one of those) can be "Adjusted" to match the product.
So far I like my LiFePO4.. NOTE: There are muliple Lithium formulations. some tend to "Flame on" (Catch fire due to thermal runaway) LiFePO4 is far less likely and the Battery Management system helps to prevent it. HOWEVER they don't like COLD weather either.. Where as a good Lead Acid can go 10-20-30 or more BELOW zero (F or C don't matter) Lithium's like to be above freezing for proper operation or so I'm told (have not tested, I bring my small one in for charging)
Hope this helps and good luck
Those battery systems sound like a good deal but not a lot of "Juice" in a single battery.
And now it's a boilerplate to save me typing.