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Build Thread: Sidetracked - mobile lounge

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“Sidetracked” captures so much of our experience already that my wife and I decided on that as our van name. We also like how it can be used jokingly as in “We got ‘sidetracked’ last weekend.” Sorry, I think that’s a bit of dad-level humor.

Our overall build objective is primarily just a comfortable place to hang out when we are in or near a beautiful place, but taking a break from outdoor activities. Think of it as a mobile living room with a couple of couches for sleeping and a small kitchen. We would also like it to serve adequately as an emergency get-away if we get caught in some kind of unfolding natural disaster that California specializes in lately. Also, as a “kitchen tent” when we go camping with our adult kids.

We expect to stay mostly in campgrounds or friends’ driveways, with only occasional dispersed camping or boondocking. The idea of just getting in the van and taking off for a week is pretty appealing.

I’m trying to keep the van operationally simple. I don’t expect my wife or kids to remember to turn on or off switches frequently to control the systems. Realistically, that’s just not going to happen. So I’m avoiding anything that has to be actively managed and anything in the engine compartment.

I’ve recently retired, so this is also a project to keep me busy ^-^

We bought a 2021 Ford Transit off a dealer lot in February of 2021. It was a canceled special order and we snapped it up immediately after our test drive for MSRP (remember those days?). It’s a 148HR AWD with factory swivel seats.

I’ve started the conversion, but everything has been moving slowly. Nevertheless there are a few interesting angles to this build and I’ll do some catch-up posts that focus on those. As a quick overview of some of the equipment and capacities:

HVAC
Dometic RTX2000 12V Air Conditioner
Propex HS2000 furnace
Floor-exiting fan
Opening passenger side window (Tern awning)

Electrical (mostly Victron and BlueSea Systems)
10,000 Wh of batteries (4 x 200AH at 12.8V)
640 watts of solar
800 watts of B2B charging
1,500 watts of shore power charging (15A shore power connection)
Victron Multiplus 12/3000 Inverter/Charger

Seating:
Front factory swivels
Two side-facing auxiliary seats in the back with seatbelts

Kitchen:
Microwave/broiler combo
Top opening chest refrigerator
Small sink / no water heater

Bathroom:
Folding toilet chair and wag bags
Sponge bath set up
Laundry bucket

Insulation:
Noico sound deadener
One layer of ⅝” Ensolite plus one layer of Thinsulate where feasible
Still working on how to deal with the back doors/side door/front cabin

Please share your feedback and suggestions as this unfolds. I very-frequently learn new things just by reading forum posts, so I know that many of you have a lot more knowledge than I do.
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I wish Sterling made a 12v-24v 120amp charger that would put out 60 amps to the 24v batteries. The options for 24V systems is to use the Orton ways of DC-AC-DC or to use multiple Victron or other DC-DC chargers. The bummer is Victron only makes a 12/24/15, so I would need 4 of those to get a 120 amp in and 60 amps out.
Supposedly 1Q 23 - Might need to get it from the UK. Not cheap. I wonder if pre-order gets charged out now. GBP is the lowest it's been in 37 yrs. Of course it could very well be even lower in 6 months given the energy situation there. :mad:
12V to 24V 120A input | 60A output Battery to Battery Charger w/ reverse charging feature
 

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Supposedly 1Q 23 - Might need to get it from the UK. Not cheap. I wonder if pre-order gets charged out now. GBP is the lowest it's been in 37 yrs. Of course it could very well be even lower in 6 months given the energy situation there. :mad:
12V to 24V 120A input | 60A output Battery to Battery Charger w/ reverse charging feature
That is a nice option. $720 USD after discount and conversion plus what ever shipping would be. Four Victron chargers would be about 2-300 more but offer a little redundancy if 1 or more failed.
 

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2020 High-Extended AWD EcoBoost Cargo with windows
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That is a nice option. $720 USD after discount and conversion plus what ever shipping would be. Four Victron chargers would be about 2-300 more but offer a little redundancy if 1 or more failed.
... or just do the DC-AC-DC thing. Seems that solution is either "works great" or something is broken and it can be fixed. The DC-DC has had so many issues - and different ones depending on the solution - thanks to our weird alternators. Quite by accident, of course, the unit we're using has such a low low-voltage shut-off that it just keeps putting out what it's asked to regardless of the alternators. Thanks to the CCP2 setup, we can even forget to turn it off and the van takes care of it. Only down-side is max of ~170A @ 12VDC with CCP2. But that's not much of an issue if you're pushing that into a Victron 3000/24/70 as it will only do ~140A equivalent of 12VDC - so you can max it... for under $400.



Do the alternators actually shut off? I didn't read anywhere that were considered smart, actually sounds energy efficient, but also dumb if you need the extra charge. haha
I can't tell and haven't investigated. Other have... perhaps they'll chime in on the official details. What I can confirm is that it is not uncommon for the voltage to be 14.5V one second and 12.1V the next while driving down the freeway - nothing changing. This is, of course, separate from the engine-shut-off at stop-lights. This has caused issues with some DC-DC units that are trying to help keep the main battery(ies) from being drained by shutting off their charging - or in the case of the data from Sterling, dropping down the amperage - to the point of shutting off eventually.

As I recently learned (thanks to someone's data here), I'm pretty sure the van's starter batteries (we have two) are making up the gap when the van shuts off at stop-lights or - potentially - if the alternator sees fit to back itself off. Again... the final outcome is that the thing just charges exactly as I expect it to all the time - unlike many of the DC-DC setups which are trying to be as "smart" as the "smart" alternators... seemingly resulting in stupid-ness from both.

Real-world: today, I left the house this morning with the 8kWh of 24VDC house batteries at 30% SOC. (I frequently let them drain and often keep them in the 60-80% range while sitting at the house.) I charged from the engine while at ~130A rate and shut it off when they hit 90%. Solar took care of the final 10% while I was snowboarding. Full batteries. No thoughts or issues. Pretty sweet.
 

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2021 Transit 148 HR
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Discussion Starter · #24 · (Edited)
Noico Butyl plus Ensolite Insulation Layers

What:
Installed a layer of butyl deadener and Ensolite.

Why: My wife and I are both light sleepers, so sound deadening when stopped is at least an equal priority to making the ride quieter. Also, since have an air conditioner, thermal insulation is critical.

An insulation layer that actually stops heat BEFORE it gets into the van interior is especially valuable. The outer skin of the van can get to over 150 deg. F, which is enough derate any wiring that's nearby, for example.
Automotive tire Hood Motor vehicle Automotive design Automotive exterior

How: Our insulation plan is basically in three layers. Sound-deadener butyl (think Kilmat), 5/8" Ensolite, 1.5" Thinsulate. And, stuff insulation wherever feasible. I've just put in the first two layers and have a quick report, especially on the Ensolite. Ensolite has a service temperature of -40 deg F to +200 deg F, which is acceptable for use against against a van wall. Not all foam is suitable for this purpose. I bought three of the 96"x58" sheets of 1/2" Ensolite from Foam N' More and have used all but a small amount. Although nominally 1/2" the foam was actually 5/8". I cut the foam with a regular utility knife (aka boxcutter), often using a straightedge to help out.

Ensolite is quite easy to work with. If you cut it a little bit large you can compress it into your install location quite easily. I adhered the Ensolite with Liquid Nails Fuze-It Max. The Fuze-it is very tacky, so even the ceiling pieces just needed to be cut to shape, coated with some lines of Fuze-it and then adhered to the ceiling. Once pressed to the surface, the weight of the material is not enough for it to sag or come off. After pushing the Ensolite against the van surface I used a rubber brayer to ensure that the lines of Fuze-it adhered well to both the van metal and the Ensolite. I did not spread out the Fuze-it on the Ensolite with a spreader or something like that. It's important to get all the air out from behind the Ensolite. I only had one bubble that I had to pierce in the whole installation. If you work from the center out with your brayer, it goes pretty well.
Black Rectangle Wood Automotive tire Gas


Fuze-it has a service temperature of -40 to 300 deg. F. This is a much wider range than many other adhesives, which was a reason that I chose it. Also, this material does not get as brittle as an epoxy, for example. I also tried a tube of a neutral cure Silicone caulk, but the Fuze-it was a bit better at adhering to the Ensolite. If I was building a recording studio type of installation I would probably go with the Silicone, but use twice as much as I used of the Fuze-it. Anyway, both work.

After installing some of the Ensolite, I checked the surface temperature with an IR thermometer and got a reading of 98.6 deg. F for the van metal:
Fluid Gadget Finger Gauge Measuring instrument

And then the Ensolite read 86.0 deg. F:
Temperature Measuring instrument Gas Gauge Machine

So a reduction of 12.6 deg. F in the surface temperature that needs to be cooled. In other words, that layer of Ensolite, although quite thin, made a very large difference in heat penetrating into the fan.

The sound reduction effect is also impressive. While you don't notice as much difference when the Ensolite is first installed, after a few weeks when the Fuze-it has cured, the sheet metal where the Ensolite has been installed is basically quite "dead". Driving the van the interior is now reasonably quiet ... like driving a passenger sedan.

It's also not bad as an "interim" look while you continue to do other work on the van. Where I had to butt two pieces of Ensolite against each other, I used a bead of black silicone to dress or fill any gap.
Hood Automotive tire Motor vehicle Automotive lighting Automotive design



Conclusion: I would definitely do the Ensolite again. While it's a bit pricey, the results are dramatic. Also, there are quite a few places where the Ensolite can be used where other insulation is awkward to apply.

A reasonable question is whether you need to do both the butyl and the Ensolite. My impression is that both help, but that doubling the amount of adhesive could completely substitute for the butyl. The butyl is primarily adding mass to the sheet metal with some vibration damping and you could do this with more adhesive as well.

For the ultimate in sound deadening, I would use a really thick layer of neutral cure silicone between the Ensolite and the van wall, but when you use more adhesive you can also have more issues with air bubbles, so the installation would be trickier.
 

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Lots of luck, For half of my adult life I slept 12 feet from a 500 Kw diesel electric generator, There were two walls between me and it and one of them was insulated with fiberglass insulation. The constant rumble and vibration was easier to sleep with then you might think, I almost miss it today.
 

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Lots of luck, For half of my adult life I slept 12 feet from a 500 Kw diesel electric generator, There were two walls between me and it and one of them was insulated with fiberglass insulation. The constant rumble and vibration was easier to sleep with then you might think, I almost miss it today.
Big, low rpm, 12 and 16 cylinder diesels in locomotives and the Alaska Ferrys- like a lullaby.
 

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2023 Ford Transit 250 AWD, HR, 148 LB
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That info from an engineer at Sterling sounds promising, but not necessarily relevant to how the Transit regulates the CCP2 output. If the Transit can't meet an amperage draw from CCP2, it's supposed to "load shed". Now it's a question of who is going to load shed first, the Transit or the Sterling. The Sterling people say that the transit will lower voltage if the amperage draw is too high. The Transit BEMM says that the Transit will load shed and drop the load. I don't really know how that will work in practice.

I'm solving for a different issue. Alternators are not always happy to run at their maximum output all the time as they can overheat. A tough scenario is stopped at idle on a hot day. In that case there is no rush of wind past the alternator cooling it. Burning out an alternator is rare, but it can happen.

I fully acknowledge that there are ways to get more out of your alternator than my design. If the Sterling operates together with the Transit as they describe, then that would be a great way to get more juice out of your alternator. If you implement the Sterling, it would be awesome if you could watch the CCP2 output amperage and see what actually happens as you drive and at idle and share that information.

The good news for you is that if you get the Sterling and have any issues with the Transit dropping the load at idle, then you can change the amperage draw in the Sterling settings. If I remember correctly there is a way to manually derate those chargers.
I'm not super familiar with the idea of load shedding from CCP2. Is that a feature that cuts off the third party loads if the amperage demand is too high, thus turning off the sterling?
Im not sure how I would exceed 175 Amps either if my sterling input is maxed at 120A?

Im reading on page 51 that Transit AWD vehicles utilize Hydraulic Power Assisted Steering (HPAS), not EPAS. On the same page, under the bolded header "Load-shedding and Standard Battery Guard" it says vehicles using EPAS are equipped with a load shedding system [...] This makes me think that AWD transits don't have this safety load shedding feature.

Your thoughts?
 

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2015 To 2019 transits were HPAS, 2020 Or newer are Epas. The 2015/19 have no load shedding, The 2020 and up do have load shedding
2019 And before one Bemm used to cover all model years, There was only one Bemm, In 2020 we got a bemm for each model year. I am guessing parts newer model year Bemm's are still a carry over from that single bemm concept with early models and later models mixed together.
 

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As I recently learned (thanks to someone's data here), I'm pretty sure the van's starter batteries (we have two) are making up the gap when the van shuts off at stop-lights or - potentially - if the alternator sees fit to back itself off.
Mr. Sterling told me that the Transit would detect the high current demand and not shut off at stop lights when charging. I would think that would also be true with the DC-AC-DC method, as the inverter/charger would be drawing on the alternators just as the B2B would be drawing.
 

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Mine does not appear to operate as Mr. Sterling may have described. If the Transit itself requires the alternator power, it may stay running. It doesn't seem to do the same with a load on CCP 1 or 2. It will auto stop and let the batteries carry the load until it restarts.
 

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Discussion Starter · #32 ·
I'm not super familiar with the idea of load shedding from CCP2. Is that a feature that cuts off the third party loads if the amperage demand is too high, thus turning off the sterling?
Load shedding is supposed to occur when the demand on CCP2 exceeds what the Transit electrical system can provide without compromising it's own needs. In other words the Transit prioritizes internal needs first (including anything connected to CCP1) and then will provide power to CCP2 up to the available amounts, taking into consideration capacity in the Transit-managed battery or batteries.

So conceptually the Transit should be able to provide over 150A when at cruising speed, but can't provide that at idle for long because it will deplete the starter batteries. Many people seem to be doing OK pulling 120A from CCP2, even though it will be too much to sustain during extended idle. So if you get stuck in traffic something has to give. Either the charger has to reduce it's load, or the Transit has to load shed, or you can manually turn off the charger if you have a switch for that.

As I mentioned before I designed my system to pull about 70A from CCP2, which is a level that the Transit can sustain even during extended idle. This means that if the van batteries get low the driver can just idle the engine and there will be enough power to charge the batteries some or run the AC. If I wanted to squeeze more power out of the alternator, I could, but at the cost of adding a bit of operational complexity. So, I chose idiot proof over optimized. Others have chosen differently.

The 175A fuse is to protect the components. That's an important number to keep in mind, but it doesn't have anything to do with the load shedding function.
 

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Mr. Sterling told me that the Transit would detect the high current demand and not shut off at stop lights when charging. I would think that would also be true with the DC-AC-DC method, as the inverter/charger would be drawing on the alternators just as the B2B would be drawing.
Can confirm that it does NOT do this. It continues to put out power to our inverter and the voltage drops. Pulling from it at ~130A, typically. It will continue to put out power even when the engine turns off - causing the voltage to drop to low- to mid-11s as the inverter pulls from the batteries (presumably) with the engine off.

FWIW, it will also continue to do this when the engine is turned off from they key until it decides to shut off CCP2 - which seems to be a blend of duration and drop in voltage. I say, "seems," because it seems to be a variable / shorter duration at times. I haven't tested or timed it since I don't intentionally do this... I've just forgotten to turn off the inverter a couple times.

As has been the case with other things on this rig, I haven't been able to make sense out of exactly why it does what it does - neither mechanically nor logically. But I can express what I've observed. In many cases, I can show the voltage changing on the starter battery as it's documented by the Smart Shunt on the auxiliary voltage input. I have alerts set up on the starter battery voltage and I'll get them from voltage dropping to mid-11s when the engine shuts off at a stop-light. Of course, they're there to remind me to turn off the inverter when turning off the engine; but they get sent every time it drops, of course. 🤷‍♀️

My belief is that the inverter we're using not shutting down until mid-10V is why it hasn't shut down on us. My belief is that most of the DC-DC solutions (all?) have a much higher voltage shut-down level and thus behave very differently. Given how they work - typically no manual on/off button easily accessible - this is probably a great backup to any other shut-down logic.

I have not seen any evidence that the Transit uses current draw / demand for anything. Maybe it does? But the fact that I can draw the voltage WAY down and it doesn't seem to react indicates differently to me. It seems that it uses the starter-battery SOC to determine the alternator charging - presumably targeting the 80% SOC as documented; but I haven't seen it operate differently based on my loads.
 

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Discussion Starter · #35 ·
Dometic RTX 2000 Installation
What: Install a Dometic RTX 2000 in the front-most position on the roof.
Why: After studying how to install a Midea U-Shaped (ultra-efficient) AC I ended up feeling like the installation and maintenance hassles outweighed the efficiency savings. The Dometic is "good enough" for what I need and is relatively straightforward to install in comparison.
How: Well first of all you have to figure out how you will support the AC during driving loads, including bumpy roads. The AC is pretty heavy at 73 pounds, so you can't just cut a hole and sit it on the sheet metal. I started by making some little blocks of plywood that could slide into the ceiling rib openings, and put in 5/16-18 threaded inserts. I put these into place using construction adhesive. Then, bent some threaded studs by 5 degrees in the middle so they could hang straight down and epoxied those in place. There are 8 studs in total.
Tire Automotive tire Wheel Motor vehicle Bumper

Then I used 3/4" marine plywood to make a support frame, supported by barrel nuts attached to the studs. I later added some stiffeners and painted this piece light grey.
Hood Motor vehicle Personal luxury car Bumper Gas

Then a sturdy frame to press right against the sheet metal so the seal would have something supporting it solidly.
Rectangle Wood Flooring Hardwood Composite material

Then cut a hole in the roof using a jigsaw. I used the full-size cutout specified by Dometic. This makes it easier to deal with the power cord, and gives a wider base to support the AC side to side.
Hood Wood Naval architecture Composite material Rectangle

Add the roof seal, some butyl tape at the ribs, and some sealant. Then added a lifting arm to the support frame that I used when working on the roof, and some pieces of plywood to support the AC while lifting.
Table Plant Tree Outdoor table Wood

Then with a few extra pairs of hands we just lifted the AC up high using a pully on an oak branch, drove the van under it and used the support frame to gently lower it in place. Then from the inside installed the hold-down bars.
Grille Hood Motor vehicle Automotive design Bumper

Whew. And that was easy compared to doing something with the Midea.
Conclusion: At the time that I did this, the Hein adapters were in their early iterations and didn't seem solid enough for me. I'd probably try to use Hein's adapters if I did this again, maybe with some additional support. Having really good support for the AC is important in every way that I can think of. I haven't gotten the electrical hooked up, but will share my experience with the AC after using it in the heat.
 

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Dometic RTX 2000 Installation
What: Install a Dometic RTX 2000 in the front-most position on the roof.
Why: After studying how to install a Midea U-Shaped (ultra-efficient) AC I ended up feeling like the installation and maintenance hassles outweighed the efficiency savings. The Dometic is "good enough" for what I need and is relatively straightforward to install in comparison.
How: Well first of all you have to figure out how you will support the AC during driving loads, including bumpy roads. The AC is pretty heavy at 73 pounds, so you can't just cut a hole and sit it on the sheet metal. I started by making some little blocks of plywood that could slide into the ceiling rib openings, and put in 5/16-18 threaded inserts. I put these into place using construction adhesive. Then, bent some threaded studs by 5 degrees in the middle so they could hang straight down and epoxied those in place. There are 8 studs in total.
View attachment 181685

Then I used 3/4" marine plywood to make a support frame, supported by barrel nuts attached to the studs. I later added some stiffeners and painted this piece light grey.
View attachment 181686
Then a sturdy frame to press right against the sheet metal so the seal would have something supporting it solidly.
View attachment 181692
Then cut a hole in the roof using a jigsaw. I used the full-size cutout specified by Dometic. This makes it easier to deal with the power cord, and gives a wider base to support the AC side to side.
View attachment 181693
Add the roof seal, some butyl tape at the ribs, and some sealant. Then added a lifting arm to the support frame that I used when working on the roof, and some pieces of plywood to support the AC while lifting. View attachment 181694
Then with a few extra pairs of hands we just lifted the AC up high using a pully on an oak branch, drove the van under it and used the support frame to gently lower it in place. Then from the inside installed the hold-down bars.
View attachment 181695
Whew. And that was easy compared to doing something with the Midea.
Conclusion: At the time that I did this, the Hein adapters were in their early iterations and didn't seem solid enough for me. I'd probably try to use Hein's adapters if I did this again, maybe with some additional support. Having really good support for the AC is important in every way that I can think of. I haven't gotten the electrical hooked up, but will share my experience with the AC after using it in the heat.
 

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geat
Load shedding is supposed to occur when the demand on CCP2 exceeds what the Transit electrical system can provide without compromising it's own needs. In other words the Transit prioritizes internal needs first (including anything connected to CCP1) and then will provide power to CCP2 up to the available amounts, taking into consideration capacity in the Transit-managed battery or batteries.

So conceptually the Transit should be able to provide over 150A when at cruising speed, but can't provide that at idle for long because it will deplete the starter batteries. Many people seem to be doing OK pulling 120A from CCP2, even though it will be too much to sustain during extended idle. So if you get stuck in traffic something has to give. Either the charger has to reduce it's load, or the Transit has to load shed, or you can manually turn off the charger if you have a switch for that.

As I mentioned before I designed my system to pull about 70A from CCP2, which is a level that the Transit can sustain even during extended idle. This means that if the van batteries get low the driver can just idle the engine and there will be enough power to charge the batteries some or run the AC. If I wanted to squeeze more power out of the alternator, I could, but at the cost of adding a bit of operational complexity. So, I chose idiot proof over optimized. Others have chosen differently.

The 175A fuse is to protect the components. That's an important number to keep in mind, but it doesn't have anything to do with the load shedding function.
Thanks! This is super helpful. I agree with you and also prefer the idiot proof method now despite the chargers ability to downrate itself, and with the transits load shedding function, it puts more on the conservative side of things. Its just that I will have 2 x 400 Amp hour batteries in parallel, and was hoping to get a faster charge while out on the road, but with the sterling 70Amp charger + Solar should be plenty to keep the juice coming in.

Few questions if you don't mind

1. CCP2 claims to be a 175A connection point. Is the 175 implying how much you can maximally draw or the fuse size? Where is the fuse located if there is one? Also is this point always turned on or is it engine controlled? Meaning its on when the engine is on and off when the engine is off. Thanks.

2. I like your AC post. Smooth work! I've been reading about various types of AC units. I'm wondering why you didn't go with a Split Vent system like a Cruise and Comfort? Its not roof mounted and so can allow for more real estate for solar, etc.. Also did you ever consider the Mabru 12V Rooftop? Its amperage range is 22-55 depending on the speed, and its cooling capacity is 12,000 BTU which is much better than the dometic RTX2000 for a similar price.
 

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Discussion Starter · #39 ·
geat


Thanks! This is super helpful. I agree with you and also prefer the idiot proof method now despite the chargers ability to downrate itself, and with the transits load shedding function, it puts more on the conservative side of things. Its just that I will have 2 x 400 Amp hour batteries in parallel, and was hoping to get a faster charge while out on the road, but with the sterling 70Amp charger + Solar should be plenty to keep the juice coming in.

Few questions if you don't mind

1. CCP2 claims to be a 175A connection point. Is the 175 implying how much you can maximally draw or the fuse size?

2. I like your AC post. Smooth work! I've been reading about various types of AC units. I'm wondering why you didn't go with a Split Vent system like a Cruise and Comfort?
CCP2 is rated to provide up to 175A maximum, and that is also the fuse size. Ford says that you can draw 175A from CCP2 indefinitely, meaning that the components can handle that load. The actual electrical supply for CCP2 is your starter battery plus alternator, so over longer period of time, like hours, you are limited by the alternator.

If you do a good job of insulating there is no need for a larger AC than the RTX 2000, so the 12,000 BTU's doesn't give you any benefit. One of the main reasons that I chose the RTX 2000 is that it's a mainline standard product from a large company and is likely to be both serviceable and replaceable. You lose the roof space only for about a 100W solar panel, so it's not that big a deal. A roof-mounted unit is really simple to deal with. The Cruise N' Comfort looks nice, but it's even more pricey than the Dometic.
 

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If you do a good job of insulating there is no need for a larger AC than the RTX 2000, so the 12,000 BTU's doesn't give you any benefit.
It is my understanding that oversizing an A/C evaporator coil is actually a detriment, since frequent cycling reduces time the coils is below dew point, hence reducing the amount of dehumidification. Rules of thumb I have seen for residential units are that 10-20 minute on cycles times are a good target. (IDK what the ACCA sizing methods shoot for).\

Of course the "building envelope" as you mentioned can have a big impact. The ability to relocate a van could increase or decrease the requirement to address ambient variation/extremes. My preference is the latter.

BTW - great job on framing structure.

OH yea, and when you get there, please report back your empirical results with the unit, "inquiring minds ..."
 
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