need a bit of critical thinking...
for my 5th-wheel, i have a 14gallon water heater, with a good tank, but bad element. now, i have a pair of 12V 600W elements from an other failed-start project. i only need one for the water-heater. my thinking is, i really can't afford a new electric-start LP water heater, and certainly can't afford a tankless. my old-old camper water-heater had a blown tank, hence me buying the 14G 110Vac (1500W) water heater, that now has a bad element.
i know how to conserve water, so 14G (or is it 20G...?) was enough before, and will be enough now. the question is, is it practical? 600W is nearly 50A! i can't run that off battery, only shore-power or generator. so would i be better off to find a 110Vac element and ONLY have hot water when plugged in? ...yes, i just picked up on the obvious answer there... either way i have to be plugged in. so really, i NEED to somehow get a RV water-heater. i can run it off 12Vdc, but for how long? i would need some pretty substantial batteries, and at least as many solar panels as the local solar-farm

so, just writing it out gave me my own critical thinking.
next order of thought... my current tanks are in better shape than i thought, i think. i looked under, and what i thought was water dripping, looks to be hardened drips of PVC cement. but i expect i will need to fill the tanks to be sure they do not leak, before committing to them. the slide valves could stand to be replaced, i think... those tend to stick and leak with age.
clean water tank... i just don't trust it. the gravity fill was open to the bugs and elements for who knows how long. i would not drink it, and who knows if it would pass the "lumps" out the drain if i flushed it. so i need to drop at least that tank, or leave it and build in a new tank. that would be classy.

why is your kitchen cabinets all without doors in them??? because that's where the water tank is...

but seriously, i either drop the tank, or find a way to clean it. worst case scenario, i put up a sign that the water is not for drinking, and store drinking water in a cooler...
i think the tank is just under the living room floor... and i don't think it is huge either (30 - 40G?). i could potentially use that tank for washing, once i get the lumps and bugs out. and get a smaller tank for the kitchen only, and plumb it to a drinking water faucet thing... 15 - 20G should hold several people a while... a 25G tank is about 34" X 17" X 10", and i could see that fitting in a cabinet area without trouble. just when i make my gravity fill connections outside, i would need two, for each tank, and label one as drinking water. not that it would make a huge difference, as it would be filled with a hose anyway.

so maybe just the one tank for fresh water, and put a boil-order on it.
one way i can think of to clean the lumps out of that tank, would be to run a hose from the gravity fill, outside. plug off the vent, and run water through the tank from the bottom up, to float out the debris (with any luck). then when i drain the tank again, run it through a paint filter (flows better than a coffee filter) to check for lumps and large grit.
moving my toilet in the bathroom to the other side of the space should be fairly easy, i think. the bathroom/utility space already has a raised floor, so i can cut a larger access hole, re-plumb the toilet flange to the other side (don't want a toilet right beside my electrical panel), and be done. i assume i can use a standard toilet flange for a house, and just bolt a RV toilet onto it???
may even move the bathroom sink over there too, to really open up the utility and master closet side of the space. i am also thinking of doing away with the AC volt and amp gauges... they are open back, and i don't like the idea of open AC gauges. they looked neat at the time, but look unsafe now that i have studied them for a while. so that's $50 down the drain... but moving right along...
the rest of the power panel is fine, i just have to run more wire for various things. A/C, outlets, and so on. all lighting will be 12V LED lighting.
I still want to change the bedroom/bathroom/utility room door from a sliding pocket door (i am a carpenter, and i hate pocket doors), to a swing door. i will use a latch similar to the entry door, just to make finding parts easy.
Still have to replace the floor in the kitchen... it is still rotted, and despite me waiting, it has not replaced itself yet. not really a big deal, i just have to get the material.
i have a large hatch on the side in back that was supposed to be for a in-board RV generator. now i am thinking of insulating it, and making it a cooler space. that way i can access the cooler from inside, or slide it into place from outside. it is a really big hatch, so i have to find a good use for it.
I had thought of moving the batteries back there, and i may still yet. wouldn't be that hard to do, really. tie it to frame ground for the negative, and run a long heavy cable for the... scratch that. not moving the batteries, but moving the whole power back there. my AC power inlet is up front, but i have plenty of 6/3 wire, so i can run that back, move the power panel back, batteries back, charger back, solar charger back (with longer wires for the solar panel hookups). it could work out better!
i could change the kitchen from a sideways U shape, to a standard U (counter on back wall, cooking and cooler on one side, power cabinets on the other (lower) side. with uppers as well. it could work out better than my first plans...
this would empty the space in the lowers of the master closet space, so i could just have some access doors down low for the wires that pass through, and the heating ducts. i could build a little bench seat in there that is removable, so i have a place to sit while i get dressed (handy as you get older

).
all these plans, i am starting to get real excited again about this renovation. 😍
sometimes i just have to talk myself into things
now, batteries... i know, there are many choices i should use, but deep-cycle marine/RV batteries from Wal-Mart are what i can afford. when i get a new battery for the camper, i will make a note of the group size for later, and check the actual size so i know how many will fit in my battery compartment. i am thinking a total of 6, if i buy as i can afford, will fit. 3 down low, and 3 on an upper shelf (welded steel, to handle the weight). i am thinking if i use Anderson connectors to connect the batteries in, with inline fuses. that will make it easier to replace in the future too. thinking either 50A or 175A. probably 50A, as with two batteries, and two 50A connectors, i can pass 100A. more than enough! heck, 50A for just one is a good start. i doubt i will be drawing more than 50A, to begin with. unless i use those water-heater elements...
~Travis