Is it possible to contact the original sell and get a full explanation of what you are looking at? If so, I'd start there and get a detailed description of what has been done. I'd encourage a non-judgmental, non-confrontational learning session. You need all the info, and if you critique, your education may be cut short.
FLA (flooded cell lead acid) batteries must be vented to operate safely, and they must be kept away from ignition sources (e.g. sparks). When working, a conventional lead-acid battery emits gasses that can explode. https://www.latimes.com/archives/la-...902-story.html
Things you need to know from the original owner:
1. Are there solar panels permanently mounted on the roof? Look for yourself.
2. If so, where is the wire routed from the panels to the charge controller and how? What gauge is the wire? It should be at least #10. How are the roof-top panels wired: all parallel; series/parallel; series? (there are advantages and disadvantages to each option.)
3. If so, where is the charge controller?
4. How is that charge controller wired to the battery bank? What gauge wire? Where does it connect (outside on the tongue or inside in Rube Goldberg heaven under the bench)?
5. How are the two battery banks connected to each other? What gauge wire is used? Looking at your floor plan, these batteries are FAR apart!! That calls for some very serious wire to connect them together to behave as one big battery.
6. Are these 6 volt or 12 volt batteries? (I can't see them clearly enough to count the cells).
7. Since many large RVs have batteries "inside" a vented space, is it possible your under-seat compartment was vented by the original owner? If so, how and where? (A forum discussion on the subject: https://www.cruisersforum.com/forums...nt-174176.html
As you might imagine, a battery explosion at sea that may cause a fire is a very serious matter.)
8. Assuming your folding (suitcase) solar panel is supplemental to roof-mounted panels, does it have its own charge controller? Does it plug into the "Zamp
" (or other brand of) quick connect on the tongue or near a cargo bay? These connections are notorious for their lack of charge controller, so you must supply one with the suitcase panel or risk damaging your battery bank by overcharging. And don't mistake a diode panel on the back of the solar panel for a charge controller. A diode panel will be "upstream" of the charge controller...first the solar panel, then the diode panel, then the charge controller.
9. If the suitcase is all there is, you need to know that, because a 100 watt suitcase panel array is hopelessly inadequate to charge 4 (or even 2) big batteries. You may need to add considerably more if you don't want to run out of battery before your boondocking trip ends (or you don't want to listen to the delightful drone of your generator for endless hours).
10. Ask for a rationale for this installation. What was the original owner envisioning when s/he made these choices? If the plan was to go out into the field with a massive battery bank and run it down...with a tiny bit of help from the inadequate suitcase solar panel...that's not a bad plan, but you need to know that plan to understand the choices made. If the original owner had the misguided notion that a 100 watt suitcase solar array could defy the laws of physics and generate 150 amp hours of charge per day, well, that happens.
Having 4 batteries on your relatively modest rig doesn't make a lot of sense...especially 4 x 12 volt batteries. Big rigs, such as fifth wheels, may run 4 x 6 volt golf cart batteries in series/parallel to deliver 12 volts, but at 65 pounds or so per battery, only one of those batteries is factored into the 809 pounds of cargo (including fresh water) you can carry. 3 more batteries eat up about 195 pounds of cargo capacity. And bear in mind that a full freshwater tank (36 gallons) will consume 300 pounds of those 800 pounds all by itself. Batteries and water together = 500 of the 800 pounds. You can't possibly get by with only 300 pounds of cargo if you plan to boondock!
What WOULD work well is a pair of 6 volt golf cart batteries on the tongue wired in series to make 12 volts. These two batteries can supply about 115 amp hours of USABLE power on a full charge, and one extra battery (and extra weight of the first battery) will account for about 75 pounds of cargo capacity.
Add in a 400 watt roof-mounted solar array...here's an example: https://smile.amazon.com/WindyNation...s%2C199&sr=8-4
You most definitely can do better with an MPPT (maximum power point tracking) charge controller instead of PWM (pulse width modulation) controller for another $100 or so. I'm using a PWM controller and doing great. Shipping weight of this kit is 71 pounds...installed weight about 60 pounds once you dump the packaging.
Lastly, the 700 watt inverter is fine as far as it goes, but what you really need is a 2KW inverter generator to make 120 volt power. Not much, whether microwave or espresso machine, can run on 700 watts. And if you want to run your micro with an inverter, it's going to eat 100 amps of 12 volt power while running. You'd need a 2000 watt inverter to power the micro, and you'd need to connect it to the battery bank with welding cable. Run the micro for 15 minutes, and you'll use 1/4 of your battery bank!! A generator is the right choice for large 120 volt loads. Let the batteries do the 12 volt work and you'll be very happy.
There a many options for generators. This is a good 2 KW model: https://www.harborfreight.com/mercha...tor-62523.html
If you envision yourself running the AC now and again, this one will do it with ease: https://www.harborfreight.com/mercha...tor-63584.html
(In most cases, a 2000 watt generator can't quite muster the power to run air conditioning.)
And, when it's all said and done, when it's raining like hell and you need to stay inside with a batch of kids, a generator will save your bacon. You can watch TV, charge devices, run toys and appliances, all the lights, stereo and more while you're hunkered down, and the genny will keep your battery bank topped off.
In conclusion, why the big diatribe? I'm not sure what you bought. A bit of a pig in a poke. I used the words Rube Goldberg...and it sure looks like it. But you have the parts and pieces of the start on a pretty good system. Ask yourself what YOU need it to do and adapt accordingly. If you're a park denizen, addicted to hookups like shore power and city water, all of this is pointless. But if you're going to boondock - really go "camping" as some of us would claim - you need to understand this stuff and start coming to grips with the fact that even god's own battery bank is a pathetic way to store power. A 5 gallon (actually 4.5) tank of propane holds the energy equivalent of 10,056 amp hours of energy. My puny 115 amp hour battery bank (a damned good one) holds 1/100th of that amount. Understanding energy, how to make it and how to consume it, is crucial to an enjoyable boondocking trip. Methinks the guy who put that "stuff" together didn't quite have a grasp on the basics. Close, but no cigar.
My rig is below. I boondock exclusively...once this summer for 10 days straight. I'm in sunny Colorado. With my new system, I am now a profligate power user...stereo on day and night, lots of lights, and so on. We even run an electric blanket for about 20 minutes through a 500 watt inverter (after quiet hours) to take the chill off the bed before we climb in. I use the genny ONLY to make lattes (yes, we are spoiled) about 15 minutes in the morning and 15 minutes in the early evening. Meanwhile, my charge controller tells my batteries are always topped off by Noon!! At 9 AM my charge controller reports about 19 amps of charge, and by Noon, it's down to a trickle, because the batteries are already full.
400 watts on the roof;
2 x 6 volt golf cart batteries;
A 2000 watt genny.