Full functional box truck conversion

[angelmander]

I posted a lot of my images in my new user thread but I want to get more feedback and talk to more people so I think this forum will be more active. I hope lol

My van is a freightliner MT-55 stepvan, its got an 88 inch by 14 foot cargo area. The thing weighs 10,000 pounds without any of the modifications I've done so far and it has a capacity of 30,000 pounds fully loaded so I wont have any weight concerns. It's a heavy duty MFer 

So far I've done both the plumbing and electrical. I ran romex and half inch PVC in the walls then put up my insulation and i've just finished paneling the ceiling. This is my first project like this but I have lots of experience with all of this type of stuff so it should be no problem. I'm happy to offer advice or help to anyone else trying to do a large conversion like mine



ask away, I really have no one else to talk to or share my conversion with so you strangers will make me happy by engaging me. Thats why I'm building this van to leave home in the first place, I cant take it here anymore

 

[66788]

Did you install your rooftop solar system and roof vents first?

 

[angelmander]

I'm not doing solar. I think solar is a waste of my time. I'm going to have a pretty hefty power consumption, nowhere near what a full roof of solar panels could accomplish and I already have a gas generator set aside for it. Don't really know what purpose roof vents would serve me

I am planning six 6 volt batteries, hooked in series parallel to give me 12 volts. this will give me a large enough battery bank to run my AC all night every night and my mini fridge and phone charging, etc. Hopefully ill be able to go 48 hours between charges, well see. When they get sufficiently low I'll run my 1000 watt generator on a 75 amp battery charger that I have and charge them up over the course of a few hours and do this as needed. No need for solar, I think its cost prohibitive and just not effective enough for the large power bank I want to have and keep up with. I'm a mechanic so I can do repairs on the generator when needed so I'm not worried about it breaking down, which it definitely will occasionally

 

[66788]

I suspect you have not adequately researched these issues before beginning your build. What you currenly have is a big oven absent climate control. The roof vents help greatly with air circulation and humidity control. I would recommend 2 vents, both powered with reversing fans, especially absent windows that open.

I live in my step van and it has 2 vents, 2 windows, and 2 doors front and rear. Without them it would be miserable in warm weather. The humidity in the winter could be very high absent adequate air circulation. If you use a buddy heater or an Olympian Wave heater, the van must be ventilated or you risk asphyxiation.

How do you plan to use the van? I find it interesting that you readily dismiss solar as "a waste of time". Please let us know.

 

[angelmander]

I have an AC unit planned in the setup. The compressor and rest of the system draw 450 watts max while running. The compressor should only have to run a maximum of half the time even when its hot because of how well insulated I have it. I think itll be fine

Without the AC, the stepvan actually stays pretty cool inside just for all the insulation I added in the build. I live in florida and in the 90 degree heat outside it stays at a tolerable temperature inside. With the side door open the aeration is adequate to prevent sweating. I plan on living in the van but I only intend to use the AC at night and it will just be warm during the days. I dont need roof vents because there is going to be a fan that I can turn on to draw air through the side vent when its pretty hot out and the roof is fully insulated anyway

 

[highdesertranger]

couple of things to think about,

six 6v batteries will not run an AC overnight.
batteries should be charged to 100% everyday letting them sit in a partially charge state will drastically reduce their lifespan. that's why solar works so well.
you want roof vent for ventilation and since hot air rises you want them on the roof.
I hope you didn't use residential solid wire romex.

highdesertranger

 

[angelmander]

Haha I sure did use solid romex. Thats what I had on hand and I have all the tools for it. My AC will draw approximately 25 amps per hour at the 12volts through my pure sine wave inverter, the total capacity of all six batteries will bring me up to about 450-500 amp hours at 12v dc. I'd be able to run it 8-12 hours a day easily and just run the generator for a few hours each day. Other appliances have a lower draw which is negligible as far as im concerned. splitting the load between six batteries means that none of the six batteries is outputting more than 15 amps at a time, so the drop in efficiency shouldnt hurt me. I doubt theyll ever collectively reach below half charge. At night it is cooler anyway so the compressor wont have to work as hard. I plan on measuring the current draw for a full day of use once everything is set up and seeing what kind of dent that puts in my system.

I dismiss solar as an option because I want my van to be a stealth conversion, and abundant solar panels on the roof would kill that idea. I wont need roof vents with a fan pulling outside air constantly into the van which already stays pretty cool in the heat of the day thanks to my bomb ass insulation XD

solar panels are expensive and dont produce nearly enough power to make a dent in my needs. I'd have to have 6 square meters of solar panels to fuel my AC unit each day for 8-12 hours. My entire roof is barely 6 square meters and the cost would be enormous for that many solar panels and that would open it up to theft.

 

[B and C]

How are you going to measure when your batteries are full? I doubt that a few hours of generator run time will fully recharge your batteries. As they get full, they accept fewer amps. If you don't fully recharge everyday, your battery capacity will dwindle. We normally refer to the first set of batteries as the learner set.

 

[angelmander]

How are you going to measure when your batteries are full?  I doubt that a few hours of generator run time will fully recharge your batteries.  As they get full, they accept fewer amps.  If you don't fully recharge everyday, your battery capacity will dwindle.  We normally refer to the first set of batteries as the learner set.

I expect to have to put about 200-300 amps at 12 volts on the batteries each day. Batteries will have a different voltage at different states of charge depending on the type of battery. I will have a digital voltometer to check them and after i've used them for a bit I will get a feel for how much I can do before needing to recharge them and how much charge I need to put on them to get them up to the necessary level. My charger should be able to do this in 5 hours max, and its a quiet enough generator to do so. I'm going to put motorkote in it and anytime it breaks down I'll be working on it. You figure an hour of running at open throttle for a generator is like a car going 60 miles, so I should get 2000-3000 hours easily out of a generator before its kapoot. using it 5 hours a day will consume maybe 3 dollars in gasoline a day and it should last over a year. It's still cheaper than paying an electric bill, even if I have to replace the generator every so often and service the battery system

 

[B and C]

Measuring voltage is the least effective way of determining charge. For a somewhat accurate voltage reading, the battery needs to be rested. Rested means no charging or discharging for at least 8 hours. If your 6 volt batteries are lead acid, I strongly recommend a hydrometer, a good glass one. Take a reading of each cell and log it.

Here is a website called battery university: https://batteryuniversity.com/learn/article/how_to_measure_state_of_charge

You will want to get your batteries back up to the full specific gravity.

I only run my generator in the morning for coffee and to give the batteries a jump on the day when they will accept a bulk charge. Solar is great for long tail charge that is required.

We have a member here that runs A/C off solar, jimindenver. Maybe he will chime in.

 

[maki2]

The great thing is you can always make changes later on if you decide they are required. No one used to have solar panels not that many years ago. The really nice quality, high CFF vent fans did not exist all that many years ago.

But I do think that a 1,000 watt generator might be a little on the under powered side for your plans. But that too can of course be changed if it does not prove to put out enough power.
You will find out if it is enough power when you get out there on the road living in your box truck. As you said you are a mechanic who can take care of generators so you certainly know more about them than many people in the forum if you have worked on them in the past.

Stranded wire is a better choice for boats and vehicles but a lot of the older motorhomes actually were wired with solid wire Romex. Apparently it was OK according to the RVIA standards as my 1980s motorhome that had solid Romex was indeed a certified RV. For all I know it might still be an approved wiring type for RVs. I am not interested enough to dig into those online document files that list the requirements for certification on the electrical standards for RVs.