Here is my solution

Crusty, you are absolutely right, when there is no voltage delta, there is no current. It is fine to have multiple charging sources at the same time, I just play safe.  Because my controllers are different brands (Sterlig and Victron), they can read battery voltage with not the same accuracy so it is possible that can work not fully in harmony. 

Thanks radin2son for your interest in my progress. So far so good, just came back to Michigan from Arizona. There are some changes in my layout: 

removed are the following - center unit, trailer hitch, Sun-Mar toilet. Stock tires had been replaced with Nitto. Added one extra leaf to rear spring. I am still in a testing mode for my water system. What I am so happy with: outdoor shower, electrical system, Espar 5kW gasoline heater, 12V Vitrifrigo fridge, Engel 12V freezer, boat hatch on the roof, Maxxfan.

For my B2B charging option, I have Sterling unit for 30A. As I have completely separate house battery system (not using body frame minus), my 2 wires from engine battery have two ON-OFF switches. Always my B2B unit is OFF and two electrical systems are independent till the moment when I want to charge my house battery from car generator. The procedure is to turn off solar panels input (to avoid two charging currents fighting each other), turn on connections to my Sterling then start the engine. I run 2 wires underneath from engine battery to the back of  my van (as per Sterling connection diagram). So far everything works as intended.

Sold to a local repair shop

This toilet was installed in my campervan but down the road it turned out that I am not using it at all. So it is for sale at $350 obo, bought it for $600 from Home Depot. Toilet has upgraded exhaust 12V fan with watertight electrical connector. Can be delivered. Right now toilet had been removed from the van and it is in storage in Kelowna BC Canada. 

Had it installed when bought my van. Never use it. Took the hitch off because my conversion turn out to be on a heavy side.

I will be in Kelowna BC Canada area for another 2-3 weeks then heading to Vancouver/Seattle area.  Can be delivered.

Asking $150 with Factor 55 lightweight 2" hitchlink receiver shackle included (no wiring harness)

All sold out or donated.

If I were you, I would keep everything as stock and somehow add this:

SEAFLO 3" in-Line Marine Bilge Air Blower 12V

Crusty, by chance do you have any pictures to share? I was considering the layout with a fuel tank in engine compartment but I dropped this idea later. I picked 5kW vs 2kW as it can be run at half speed to make enough BTUs. So less noise and stress on the heater. Dimensions wise is not a big difference. 

Espar Airtronic B5 Air Heater 12 Volt Version had been installed at rear right corner. It is very quiet (I have no idea what people are saying about its pump clicking noise) and makes a lot of heat. 

Interior lighting.pdf

As I have one Maxxair at the very back this vent openings will provide cool cross flow breeze (pull out mode).

There is a marine hatch next to Max fan but I found very little air flow between them because they are close to each other. 

Here is installed window air vent insert in the window channel of my passenger door. 

Screen has two halves with magnets to close. Test runs after installation shown no issues to get in/out. However only real life usage will tell all pros and cons.  

 

Local Apparent Friday,

thanks for your appreciation of my build. Will be happy if it will motivates you for the modifications. 

That is why I have a modular units system with 80/20 extrusions/components all around to make easier my future's changes. If you will come up with something revolutionary, changing your layout, I will be able to borrow your ideas and to do fast implementation.  

The rear screen is very flexible and slider one is quite rigid so it gives that appearance difference. Moneywise $97 vs $349

If you are looking for a bug screen, here is what I installed.

 

Rear:  https://www.amazon.com/dp/B0BQKJLT8B?psc=1&ref=ppx_yo2ov_dt_b_product_details

Fit is exact as it was designed for high roof NV. Shown below are two set ups -  for both doors opened and just for one.

 

Sliding door: modified Sprinter 2003-2006 T1N version from BugWall. Ask Dutch (dutch@thebugwall.com) for details.

 

1.     Classic Accessories PolyPRO3 Deluxe Class B RV Cover (used for one winter, in great shape, there is only one place with 10"-12" seam split – easy fix with sail patch repair tape)…. $25

2.     HitchMate tirestep adjustable step…. $10

3.     New Renogy 12V Eclipse Monocrystalline High-Efficiency Solar Panel 100W 2ps… each $50

4.     Never used Inergy Ascent 100W Folding Solar Panel…. $50

5.     RAM universal laptop mount w/adjustable base.. $15

7.     New Hepfner gear case rack 2ps…. each $5

8.     New Honda generator EU2200i muffler…. $20

9.     Some leftover materials/parts.. if you take everything shown - $15 or $1-free by piece  

Location: Rochester, Michigan

My main field of expertise is automotive with natural curiosity for any mechanical/electrical devices

6gal for solar tank, 10gal for the main one and 3x20L jerry cans

yes, taking earlier retirement from one of OEM.. this NV conversion will be my last project.. trying to learn how

to age gracefully  

Sharing to the community my gravity feed/solar heated water system implementation. 

Functions achieved:

-Simple shower set up

-Easy water level monitoring

 

 

 

 

 

 

 

yes, soon i will start doing full time in this van with a maiden voyage to BC Canada. I made a component list for everything electrical (not sure if something is missing) with some pics as well on the subject. Other lists for different systems will follow.

 

Renogy Eclipse Solar Panels 4ps total 400W

Lithium Battle Born deep cycle batteries 3 ps total 300Ah

Engine battery X2 Power model SLI27FAGMDP

OzCharge Rescue Mate 12-Volt Super Capacitor Jump Starter – 750 Amp

 

From Blue Sea Systems:

 

1733-BSS Mini Digital DA Voltmeter

Dual USB Chargers

Temperature Monitor ‎1741

5025 ST Blade Fuse Block 6 Circuit

5045 ST Blade Fuse Block Compact 4 Circuit with Cover

A-Series Toggle Single Pole Circuit Breakers

Weather Deck Waterproof Panels 4 pos fused

12V Socket

6010200 m-Series Battery Switch Dual Circuit

9003E e-Series Battery Switch, On/Off (to disconnect winch)

2723 Dual Bus 150A Common 4 x 5/16" Stud and 5 x 10-32 Screw Terminal

Rocker ON-OFF Switches

5191 Fuse Block Terminal 30-300 AMP

Terminal Feed Through Connector

5117 225A Class T Fuse

 

From Victron Energy:

 

SmartSolar MPPT 100/50

MultiPlus C 12/2000/80-50 120V (UL 458) Inverter Charger

BMV-712 Battery Monitor with Bluetooth Built-in

Color Control GX

Digital Multi Control 200/200A

Temperature sensor for BMV-702/712

Orion-Tr IP43 12/12-Volt 18 amp 220-Watt Isolated DC-DC Converter

Battery Alarm GX

CCGX Wi-Fi Module Simple (Nano USB)

VE.Bus Smart Dongle (Bluetooth)

VE.Direct Cables

Wall Mounted Enclosure Panels

RJ45 UTP Cables

 

Sterling DC Battery to Battery Charger 24V-12V 35A

Sterling White Remote BBURC

Bosch 0332019157 Normal Open Mini Relays - 4 Pins, 12 V, 40 A

All cables are from Battery Cables USA

All wiring done with Ancor Marine Grade Primary Wire

Sirocco II Fan, Omni-Directional Gimbal Fan 12V
 

MaxxAir Maxxfan 00-06200K

Vitrifrigo VF62 2.2 cu ft fridge

ENGEL 17 Quart top-Opening 12/24V DC - 110V/120V AC Fridge-Freezer

Furrion RV Electric Induction Cooktop 1500 Watt model FIH1ZEA-BG

Dream Lighting 12V 3.5inch LED Luxury Crystal Panel Light

Lunasea Adjustable Linear LED Light w/Built-In Dimmer – 12”, 12VDC

MASO 12V Spot Reading Light Interior Lighting Wall Lamp with Switch

Wago 221-612 LEVER-NUTS 10AWG 2 Conductor Compact Wire Connectors

Bussmann BP/ATM-2 Fast Acting Mini-Fuses

Bussmann HHL In-Line ATM Fuse Holder - 32V/20A - #16 Wire Leads

Brandmotion Rear Camera 9002-7608

Brandmotion AHDS-7650 Universal 5" Digital Display Monitor

AIDA 2ft Auto Reset 12/3 Gauge SJTW GFCI Extension Cord, 15 AMP

NOCO GCP1E 15A AC Port Plug 6ft Extension Cord

Marinco 15A Marine Grade Locking Extension Cord

LogicBlue Technology LevelMatePRO+ Wireless Vehicle RV Leveling System

Diode Dynamics Stage Series 3in SAE/DOT Type FT Fog Light Kit

Heavy Duty Dual Output Light Bar Wiring Harness Diode Dynamics

Sensorcon Inspector CO Carbon Monoxide Monitor

Starlink mobile internet

BUD Industries AU-1028 Aluminum Utility Cabinet 3" L x 5" W x 4" H (used as entry points for cables where plastic ventilation box is located)

Hi, here are some pics showing the result of my  exciting 3 years building journey. It is time to start using it. 

If there will be questions about systems, parts, materials and such, please, ask me.

For sale front/rear bumpers and tow hooks. 3 years old (replaced with Aluminess bumpers) with no damage. There are some cosmetic rust spots. Asking $120 for the whole package. 48306 location in Michigan