Author Topic: Cargo Van Conversion To Camper Van - Electrical systems  (Read 2217 times)

Cottonswab

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Cargo Van Conversion To Camper Van - Electrical systems
« on: October 27, 2016, 02:59:11 AM »
UPDATE 11/6/2016:
After following some of the advice in this thread and doing the math, I think I have a fairly robust concept for the electrical system.  My assumptions and calculations are attached. 

I plan to install solar panels on all of the available roof space (avoiding any overhang).  My solar capacity will likely max out at 500-600W.  The solar panels, alone, will likely not meet my daily energy needs, unless I use hydrocarbons for cooking or turn off the refrigerator.  However, given that the cost of induction stoves and propane stoves is relatively low, I will likely buy both.  I will plan to use the induction stove, when I will be driving enough to recharge with the alternator.  The van OEM alternator is rated at 14V / 220A, and can provide a day's worth of electricity for ~1 hour of driving.

In the winter, I should be able to turn off the refrigerator whenever ambient temperatures are low enough that I can refrigerate items outside (or inside!) the van.

I will also be able to save energy by not using my laptop or the 12V lights, when camping in the backcountry, which will further reduce my energy loads, when I am not driving. 

At this point, I will be focusing more on detailed design and how to make the system as efficient as possible.  My new questions are:

  • Should I use Lithium Phosphate or AGM for the house batteries in the cargo/living area? 
  • Will it be more efficient to use a 12V, 24V, or 48V energy generation and storage system, when using
       - AC induction stove that runs on 120V AC
       - Refrigerator that can run on 120V AC, 12V DC, or 24V DC power.
       - Laptop that requires a 16V DC input. 
  • I am planning to have a 12V / 100 A-hr lead acid battery installed in the engine compartment with a cut-off relay, in addition to the starter battery.  What is the best system of diodes / cutoffs / controllers to use for a second relay to the main house batteries that will be stored in the cargo area? 
  • Should I install rigid or flexible solar panels?  I am currently leaning towards installing rigid solar panels with tiltable mount.


ORIGINAL POST:
I am looking to buy an un-improved cargo van and convert it into a camper van (my primary residence).  I need advice on design, procurement, and installation of the electrical system.

At the moment, I will most likely end up buying a Mercedes Sprinter Cargo Van.  Unfortunately, I do not have any previous electrical experience, and I don't want to make any costly screw-ups.  I want to install: solar panels, charge controller, cut-off relay from alternator, auxiliary batteries, roof fan, refrigerator, pure sine-wave converter, ceiling lights, and electrical outlets for occasionally used appliances (induction stove top, laptop, tablet, hand-held vacuum). 

My needs will not be substantially different from most van dwellers.  So, I am looking for the following:

  • detailed electrical design drawings
  • procurement list for the electrical components
  • list of required tools
  • step-by-step instructions

Where might I be able to find the items listed above?
« Last Edit: November 06, 2016, 05:03:51 AM by Cottonswab »

Caoineag

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #1 on: October 27, 2016, 09:15:17 AM »
http://roadslesstraveled.us/batteries/

You want to check out this website. Best explanation and they have done it on rvs and sailboats. Very comprehensive explanations. :)

zolotiyeruki

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #2 on: October 27, 2016, 09:28:51 AM »
I'm an EE, so I'd probably do things a bit different than most people, but here are a few thoughts:
Solar panels and batteries are DC.  Also, they're limited in their storage and output.  Any time you convert from DC to AC or back, there are losses, usually at least 20%.  So the more you can keep everything DC, the better.  I'd run 12V LED lighting throughout.  I'd use DC fans, get a 12VDC fridge, use buck converters (which can be *very* efficient) to get 5VDC from 12VDC for the usb-powered stuff, and get a car adapter for your laptop that simply boosts the car's 12V up to whatever DC voltage your laptop takes.

WRT cooking you'll probably be better off running some sort of propane system.  Cooking requires a *lot* of energy, and in the winter months, you won't be getting nearly as much from your solar panels, which means your engine would have to be running to spin the alternator to produce enough electricity to run your cooktop.  That's rather inefficient.

Syonyk

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #3 on: October 27, 2016, 03:14:01 PM »
My needs will not be substantially different from most van dwellers.  So, I am looking for the following:

  • detailed electrical design drawings
  • procurement list for the electrical components
  • list of required tools
  • step-by-step instructions

Where might I be able to find the items listed above?

I suggest spending some time on van dweller forums (which I know exist), and learning what you're doing with electronics.  An off grid system is not as easy as a grid-tied system ("turn switch on, power arrives"), so you need to understand the system a lot better to maintain it.  Especially with lead acid - the deep cycle ones are touchy.

You'd also be better off with propane for fridge and cooking.

Summer?  No problem.  Do whatever.

Winter?  Problem.  You'll either need to be able to run on very little power, or run the engine to charge things.  If you do run the engine, I suggest getting a high idle chip and a heavy duty alternator, with a charging isolator so you don't pull power off the starter battery (it won't like being asked to fill a large deep cycle bank).

Also, whatever you end up with, get an inverter/charger so you can charge the battery bank if you're at a camp site with shore power.  Aims Power makes some nice off grid units that work fairly well.
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Left Bank

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #4 on: October 29, 2016, 09:48:16 PM »
You may want to wade through the expeditionportal.com forums too.  There is a whole section on electrical power systems. Great info for vehicle builds and plenty of helpful folks.
Good luck.
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paddedhat

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #5 on: October 30, 2016, 09:54:40 AM »
I'm an EE, so I'd probably do things a bit different than most people, but here are a few thoughts:
Solar panels and batteries are DC.  Also, they're limited in their storage and output.  Any time you convert from DC to AC or back, there are losses, usually at least 20%.  So the more you can keep everything DC, the better.  I'd run 12V LED lighting throughout.  I'd use DC fans, get a 12VDC fridge, use buck converters (which can be *very* efficient) to get 5VDC from 12VDC for the usb-powered stuff, and get a car adapter for your laptop that simply boosts the car's 12V up to whatever DC voltage your laptop takes.

WRT cooking you'll probably be better off running some sort of propane system.  Cooking requires a *lot* of energy, and in the winter months, you won't be getting nearly as much from your solar panels, which means your engine would have to be running to spin the alternator to produce enough electricity to run your cooktop.  That's rather inefficient.

You have largely described how a modern, fully self-contained recreation vehicle operates, with a few exceptions. Those being:

1. Solar is used extensively by a limited number of RVers.  handybobsolar  is a great blog on how to do it right without spending a fortune on inferior, but greatly hyped equipment. Technomadia is a great blog by a couple that really pushes the envelope on what's possible with mobile solar dwelling.
2. Propane is the dominate fuel for refrigeration, heating, cooking and water heating. All are perhaps possible with solar, but the cost/benefit analysis doesn't pencil out too well.
3. AC is pretty much unavoidable, since you are occupying a lightly insulated metal box. Solar really isn't an option, limiting the use of AC to being powered by a generator, or being plugged into a 120V AC power source.

When it comes to van dwelling  cheaprvliving.com is probably the most comprehensive source out there.

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #6 on: November 01, 2016, 07:23:26 AM »
Have you ever seen a Honda generator up close?

Honda makes a series of generators with lawnmower engines. They get the job done well but are noisy.

They also make a series of generators that are quiet enough that you can stand right next to it and have a normal conversation.

Now, other brands are following Honda's lead into quiet generators. The good ones even have an ECO switch that allows the generator to idle down if there isn't much load on the generator making it quieter and more frugal with fuel.

I know at least with the Generac and Honda brand generators you can electrically tie two together to double the electrical output if you needed/wanted to. You can also plumb the generator into a larger gas tank so it runs more than 4-5 hours per fillup.

Several times a year as part of my job I spend a few days testing equipment out in the field. Rather than high idle a $10K+ truck engine, I'd use a little generator. I have the Honda EU1000 (1000W) for computers. I also have the Honda EU6500W that runs just about everything. This big generator is big and heavy so its not likely that you'd just stuff this into a van for a weekend trip. The little 1000 series generators are small and would fit under a back seat in alot of converted van/RV vehicles.

Its easy to let your equipment list grow until you don't fit into a van anymore. I once thought those motorhomes were silly - why so big? I get it now for long term travel. Part "look at me" and part once they made their packing list they needed a Greyhound bus to haul it all.

We use a small van with a basic interior (storage, seats that convert to beds, we cook outside), LED lights and a fan. We rely on the campground facilities for toilet and showers. I also drag along a Brenderup 1205S trailer for our bikes and whatever else we need for the "deluxe" experience. ;)

I don't haul anything dangerous inside the van with us so big propane bottles or gas cans ride in the trailer. We don't camp with a generator but I have a tiny inverter (600W) that I run if I need to charge up a battery. In most of the campgrounds we frequent we have 120V supplied so we won't need the inverter and it just stays off.

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Syonyk

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #8 on: November 01, 2016, 08:06:35 AM »
Now, other brands are following Honda's lead into quiet generators. The good ones even have an ECO switch that allows the generator to idle down if there isn't much load on the generator making it quieter and more frugal with fuel.

The "Eco" switch will let them throttle down, but you're still better off running a generator at 50-70% load, efficiency-wise, and then just turning it off and using batteries when you need a light load.

You can find Kipor generators, which are sort of a Honda clone, for about half the price.  Though be aware that if you get a used one, you'll probably have some fiddling around to do.  They don't seem to like ethanol in the fuel system.  I've got a leaking fuel pump in mine, which needs to be replaced.
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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #9 on: November 01, 2016, 08:40:45 AM »
Thanks for the brand recommendation. i never heard of them.

FWIW the Honda style generators are inverter generators.

Harbor Freight and some of the tool stores also carry tiny ~1000W generators for ~$150 but those are not inverter generators and thus not as quiet. Think leaf blower or weed wacker noises. ;)

The inverter generators are able to run at different RPMs and still make 120V/60Hz. The older style generators must run at ~3600 rpm (like the older style big generators) to make that 60Hz power. That higher RPM comes with a noise penalty.

http://www.yamahaef2000is.com/conventional_generator_vs_inverter_generator.html

I agree - charge up those batteries and avoid running a generator.

I'd go for max efficiency of devices as mentioned earlier by zolotiyeruki and others here. Add several rooftop solar panels.

Tie the house batteries into the vehicle charging system when the engine is running so each time you switch off the engine, the "house batteries" are as close to 100% charged as possible. That's what I do using a relay that closes each time the engine is running thus connecting the house battery to the cranking battery. 

If we get up in the morn and drive 50 miles, the battery is being charged. By nightfall if we've toured, its charged. Alternatively with solar, even if you didn't tour during the day, the solar panels could have the batteries topped off if you don't camp in the shade. I've seen people who like to camp near the seashore employ a small wind turbine ~20 ft off of the ground too.

Air conditioning would be a challenge on batteries. I don't think it can be done without a Tesla size battery. I would be inclined to explore using a reflective tent over the roof to minimize solar gain (temps increase) inside the van and use a small fan to cool us while we sleep. We tend to camp in the cooler months so we work at heating more than cooling.

http://www.mrheater.com/product/heaters/buddy-series.html

paddedhat

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #10 on: November 01, 2016, 09:26:14 AM »
I have used my Honda 2000 extensively (hundreds of hours) while building homes. They are quiet, reliable as an anvil, and do have the low idle switch. The problem is that they run rich on low idle, and will fowl plugs. Not a huge issue, but I wasted time ,and money, sending it to the honda shop, until I figured it out. Any time a little genny like this starts to run poorly, pull the spark plug and take a look. I now keep a couple of NGK brand plugs, and the correct socket with me, when I'm using it. Just my opinion, but I wouldn't waste time on any of the half priced knock-offs of these inverter generators. They are half price for a reason, and the net is full of people who wasted a ton of time an effort trying to keep them running reliably, and often ended up disposing of them after the got a decent Honda, Yamaha, or equal.   

Syonyk

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #11 on: November 01, 2016, 09:30:48 AM »
Just my opinion, but I wouldn't waste time on any of the half priced knock-offs of these inverter generators. They are half price for a reason, and the net is full of people who wasted a ton of time an effort trying to keep them running reliably, and often ended up disposing of them after the got a decent Honda, Yamaha, or equal.

I own a cheap one, and so far I agree with you.  Currently, my $300 generator (Kipor rebadge) needs the fuel pump replaced, and I have to bypass the oil level shutdown to get the thing to run.  I just manually check the oil level then plug that connection in later, but I think it's gunked up and sticking.  So... on my list of things to do when I pull it apart.

Quite tempted by the Hondas...  Just... $1000. :(
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Cottonswab

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #12 on: November 01, 2016, 11:17:18 AM »
Thanks to everyone who has provided advice and/or references!

I have been spent a lot of time down the rabbit hole: doing research, calculations, and assembling spreadsheets.  I will update the OP with the additional details soon.

To clarify a few items of discussion thus far:
  • I fancy myself to be a bit of a "hard man" and can tolerate / enjoy wider temperature ranges and less comfortable living conditions than most people.  I am used to living out of a backpack with nothing more than a ultralight tarp, short sleeping pad, and/or bivvy sack for shelter for weeks at a time (at temperatures as low as -20 degC).
  • I am currently attempting to go for an all solar / alternator electricity generation build.  I want to avoid the use of propane for regular cooking or refrigeration.  I am still working through the calculations to determine whether I will be able to consistently generate enough energy meet all of my energy demands.  The current limiting factor right now is the surface area of my roof / photovoltaic energy conversion efficiency.  I have an isobutane mountaineering stove, for emergencies, when I don't have enough electrical power.  I will likely consider adding a human powered hand/pedal backup generator, before considering adding a fuel fired backup generator
  • I do not foresee a need for AC or regular heating. I will be installing "a lot" of insulation to minimize conductive, radiative, and convection heat transfer.  The cargo area will not have any windows (i.e., uninsulated surfaces.  The van will have electrically heated seats for emergencies where I require exogenous heat (hypothermia) or need to dry out damp clothes.
  • With the possible exceptions of Cascades Westside and Squamish, I plan to spend most of my time in places that get a lot of sunshine and have limited cloud cover.  I don't mind renting an apartment during winter months, if necessary.

My biggest question at the moment is: which currently commercially available solar panels will provide the highest energy density?  I would like to get a 800W solar panel array, but I have not been able to confirm that this is feasible with roof dimensions of 11.5' L x 5' W (while leaving space for 14" x 14" Fantastic Vent Fan). 
« Last Edit: November 01, 2016, 11:23:48 AM by Cottonswab »

mskyle

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #13 on: November 01, 2016, 01:23:41 PM »
My sister lives in a converted Sprinter and last I heard (we live on opposite coasts) she only had 2 100-Watt panels for her fridge and electronics (lights, computer, phone); she does cook with propane, though. 800 watts seems like a lot of power for your needs. (I think she did also recently install a diesel heater - she had been using a dog for heat but she's going on a months-long ski adventure this winter.)

Syonyk

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #14 on: November 01, 2016, 01:47:38 PM »
I am currently attempting to go for an all solar / alternator electricity generation build.  I want to avoid the use of propane for regular cooking or refrigeration.

Ok, so "alternator based."  You're not going to generate much solar from a van top, and if you feed it through lead acid, the round trip efficiency will hurt you.

If you want to avoid the use of propane, then you're going to want to avoid the use of refrigeration.  There's a reason most off-grid type use propane for fridges, and it's not because they love propane.

Quote
I am still working through the calculations to determine whether I will be able to consistently generate enough energy meet all of my energy demands.

If you want to run the engine & alternator frequently, yes.  Based on pure solar, maaaybe in the summer.  Iffy, but possible.  Fall/winter/spring?  Generator time.

Quote
The current limiting factor right now is the surface area of my roof / photovoltaic energy conversion efficiency.

That's not the real problem.  The real problem is the dogged persistence of the sky in having clouds and the like, refusing to let the sun hit your panels.

I've got a 3kW system.  On a bad day, I'm lucky to get 150W out of my panels, so I run the generator.

Quote
I will likely consider adding a human powered hand/pedal backup generator, before considering adding a fuel fired backup generator

If your process involves "I'm going to pedal and create electricity," you're heading down a road full of pain and dark nights.

Quote
My biggest question at the moment is: which currently commercially available solar panels will provide the highest energy density?  I would like to get a 800W solar panel array, but I have not been able to confirm that this is feasible with roof dimensions of 11.5' L x 5' W (while leaving space for 14" x 14" Fantastic Vent Fan).

11.5' x 5' is ~5 m^2 - so you *might* be able to get 800-1000W of high efficiency panels hung, not that you'll ever see that unless you put together a pretty fancy tilting system.
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Syonyk

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #15 on: November 01, 2016, 01:48:52 PM »
My sister lives in a converted Sprinter and last I heard (we live on opposite coasts) she only had 2 100-Watt panels for her fridge and electronics (lights, computer, phone); she does cook with propane, though. 800 watts seems like a lot of power for your needs. (I think she did also recently install a diesel heater - she had been using a dog for heat but she's going on a months-long ski adventure this winter.)

800W is the nameplate rating on the panels - they'll never produce that if installed on top of a van "flat" - and they'll probably never produce it anyway.  Panel rating is goofy.

Propane solves an awful lot of problems.

But, I have to say, the band was named after a "three dog night" not "dog and a diesel heater." ;)
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mskyle

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #16 on: November 01, 2016, 02:30:40 PM »
Propane solves an awful lot of problems.

I suspect "just not cooking very much" is the main way she solves her problems! (She waitresses when she's not on the road, which helps.)

paddedhat

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #17 on: November 01, 2016, 05:14:36 PM »
Just my opinion, but I wouldn't waste time on any of the half priced knock-offs of these inverter generators. They are half price for a reason, and the net is full of people who wasted a ton of time an effort trying to keep them running reliably, and often ended up disposing of them after the got a decent Honda, Yamaha, or equal.

I own a cheap one, and so far I agree with you.  Currently, my $300 generator (Kipor rebadge) needs the fuel pump replaced, and I have to bypass the oil level shutdown to get the thing to run.  I just manually check the oil level then plug that connection in later, but I think it's gunked up and sticking.  So... on my list of things to do when I pull it apart.

Quite tempted by the Hondas...  Just... $1000. :(

Over the long run, the painful upfront cost is worth it. I abused the shit out of mine, and about the only sin that I failed to commit was to run it out of oil, which wouldn't matter anyway, since it shuts itself off if you try.  I've left untreated gas in over the winters, fowled a ton of plugs, left it running out in the rain (uncovered) repeatedly, changed the oil on rare occasion, and it never skipped a beat. Last summer, I fired it up for the first time in two years.  I put fresh gas in, and it started on the second pull. The crazy part is that it paid for itself a few times over. While framing, or doing rough in for mechanicals, I previously used a 5500W five horse construction generator. That noisy, touchy, moody POS would suck down a bit over five gallons a day. When I left it in the shop and switched to the honda, my daily fuel use dropped to a bit over a gallon a day. I've had it for a decade, and back when gas was $4/gal. I figured that every three months of use, it paid for itself again in fuel savings. If it threw a rod, the next time I use it, I would hold a respectful burial, thank it for it's exceptional service, and buy another one. It doesn't owe me a penny.

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #18 on: November 01, 2016, 07:13:18 PM »
I don't mind moderate maintenance - a fuel pump isn't a big deal, and I'm putting the Honda OEM pump in, since it's basically the same thing.

If it refuses to start some dark and cold winter day, I'm driving up to buy a Honda.  The Honda is still less than the cost of my battery bank.
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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #19 on: November 02, 2016, 09:37:53 AM »
Anyone have experience with the Generac?

I have used a Coleman (B&S engine) noisy generator for many years before the Hondas. It was die hard but every once in a while randomly it would try to stall and sputter and then we'd start praying and saying nice things to it and it would recover. Never did solve that mystery. It got to be entertaining but I'd worry we wouldn't get our work done if it died and refused to restart.

I hated the noise though of the old style 3600 rpm generators. I'm spoiled with that Honda EU6500 (quiet) ginny.

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #20 on: November 06, 2016, 05:06:00 AM »
I updated the original post with details of my selected concept for the electrical system and a few optimization questions. 

zolotiyeruki

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #21 on: November 06, 2016, 06:47:40 AM »
I'd opt for the AGM batteries.  Cheaper, more mature, simpler to charge, etc.

A higher-voltage storage system will be slightly more efficient (fewer switching losses) if you can charge directly at that voltage, rather than through a boost circuit, but a 12V system you can hook up to just about anything.  I don't have much other advice.

I still think you're going to be disappointed if you stick to electric for cooking.  It feels like you're giving up on a lot of things (lighting, refrigeration, etc) just so you can stay within your power budget.

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #22 on: November 06, 2016, 04:26:13 PM »
Should I use Lithium Phosphate or AGM for the house batteries in the cargo/living area?

You're planning to live in it full time?  LiFePO4 is the way to go.  AGM is low maintenance for lead, but they're a bit touchy.  If you're going to be chronically undercharged (which you will be), lithium handles it a lot better.

Quote
Will it be more efficient to use a 12V, 24V, or 48V energy generation and storage system, when using
   - AC induction stove that runs on 120V AC
   - Refrigerator that can run on 120V AC, 12V DC, or 24V DC power.
   - Laptop that requires a 16V DC input.

24V is probably fine.  Do the math on watts - you don't really want to be pulling >100A out of your battery, as wiring gets more complex.  I've got a 48V system for a ~2000W peak draw and it's easy enough to maintain.

One downside of a higher voltage system is that you'll need a boost converter to charge from your truck 12V system.

Quote
I am planning to have a 12V / 100 A-hr lead acid battery installed in the engine compartment with a cut-off relay, in addition to the starter battery.  What is the best system of diodes / cutoffs / controllers to use for a second relay to the main house batteries that will be stored in the cargo area?

So... starter battery, 12V lead acid under the hood, then hotel batteries?  Why the second lead acid?  I'd just spend the money on the hotel pack.

Quote
Should I install rigid or flexible solar panels?  I am currently leaning towards installing rigid solar panels with tiltable mount.

Rigid panels will have the advantage of having a gap between the panels and your van roof, but will require stronger mounting if you want to travel at highway speeds.
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Cottonswab

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #23 on: November 06, 2016, 07:53:11 PM »
Thanks for the advice everyone.  I just stumbled upon the following site, which would appear to provide the level of detail I am looking for at a reasonable price.

http://cargovanconversioncourse.com/thb

Has anyone tried this cargo van conversion course?  If so, do you recommend it?

GuitarBrian

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #24 on: November 07, 2016, 12:54:42 AM »
I live full time in a small RV (8.5" camper on the back of a truck).

I have also lived the last 20+ years on a sailboat (never at a dock, always on anchor) 3 to 8 months at a time.

This might get long, I hope to help you, and hope you know that I have real experience in this subject. Also, I am frugal and not going to refrain from recommending anything too expensive.

First, I will point out a often overlooked flaw with the Sprinter van. It isn't 4wd. This may not be a problem for some, but at the price they command, it is a problem for me. I spend 2 months a year in the mountains hunting, and winters in Baja on the beach, in sand. No vans make it past the first mud or through the sand. Now, 4wd isn't perfect, but in mud, snow, ruts and steep areas, without it, you don't go. Every year we finish up hunting in a snow storm with 12 miles to get out, across slippery mud and muck. Chains all around is required and so far, in 28 years, twice we used our 9000lbs winch.

For driving on improved roads, the Sprinter is great.

I wrote a post here talking about my reasoning that there are other options to look at... let me see if I can find it...
http://forum.mrmoneymustache.com/welcome-to-the-forum/fire-in-a-sprinter-van/msg582026/#msg582026

What you are proposing can be done, and available solar power *shouldn't* be the limiting factor.

You can use 3 SunPower e327 panels. (Or the X335/X345 panels) They are 5 foot long, and 41" wide. There will be about a ~14inch gap for the vent.

First, your biggest power drain will be the fridge. This is a terrible type of power drain, constant and basically never ending. You would be WAY ahead to use a propane fridge. But, fear not, you can use an electric if you choose. I would recommend a marine 12v fridge. This will set you back as much as an RV propane fridge, but when going electric is going to be a *MUCH* better choice than a dorm 120v $79 costco special.

We have a norcold with a custom built insulated box. It draws 25 watts and runs 24/7 (it is in a hot environment, night time lows average 85 and daytime is 93). A bit like this, http://www.westmarine.com/buy/norcold--universal-voltage-marine-refrigerator-black-2-7-cu-ft--14000830

Assuming you use something like that for refrigeration, I know that one 327w panel will run that just fine with 2 golf cart batteries. In decent sun.

So, wire each panel to a 30amp Tracer MPPT charge controller (eBay $109) these have been working great for me.

Start with 6 or 8 golf cart batteries (I would do 6 and see if I need more)

I am on the computer all the time, laptops are very power efficient. Use the power during the day to charge and use the laptop, then use the battery at night, if you are like me, I get about 6 hours from my MacBook Pro 2012, and then plug in after that if needed.

Get either a manual or automatic disconnect for the starter battery, so you don't have to worry about running the starting battery dead. And can (if you choose, charge the batteries with the alternator)

Use LED 12v lights, they are cheap (look on ebay) and all the rest of your power usage will be minimal.

I have a 2000w Xantrax Pure Sine wave inverter. I like it, the fan never runs and I leave it on all the time. Other brands are available of course, but it was cheap and works good for me.

On my camper, I only have room for 1 panel, and with it, I have 4 batteries. With this setup, I went all summer without running the generator once.

When we went hunting, we brought a chest freezer, with ice cream and meat etc. The single solar panel ran the freezer, computer, TV, charge phones, lights, water pumps, electric chain saw, dehydrator (<-- that sucker used a lot of power), and anything else 4 people spread out between my camper and a trailer (I ran a 12v cord to the trailer battery to hook them up) could use... for over a month. I didn't run the engine or generator AT ALL. I ran the freezer 4 to 5 hours a day, during the day. It was cold enough at night to be OK.

But, when I got an elk and we needed to get it frozen, there wasn't enough power to run the freezer all day and all night. So for 3 days I ran the generator (A Honda EU2000) it used 2 gallons of gas per 24 hours. Then put it away and the solar took over.

The Honda EU2000 will also run my A/C in the camper, I have only run it for about 4 hours at a time, And it didn't use a full tank (1 gallon) in that time. It will run any ~5000 BTU AC.

But the difference is I am not running an electric refrigeration system. It is propane, As is my heat, cooking, and hot water. So one panel is enough.

So, If one panel is enough to cover all my regular usage, and I know that one panel will cover the refrigerator (as it does on our boat) than I feel confidant in recommending this setup and feel it will serve you well.

If you need wiring diagrams or any other questions, I will be happy to help.

TL/DR I recommend 3 large grid tie panels (~1000 watts), 3 inexpensive MPPT controllers, 6-8 Lead Acid Golf Cart Batteries, system at 12v to simplify wiring, lights and hooking up to the alternator. An efficient 12v refrigerator, and a Honda EU2000 for backup and A/C use.

Playing with Fire UK

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #25 on: November 12, 2016, 10:57:02 AM »
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Cottonswab

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #26 on: December 09, 2016, 02:29:39 AM »
First, I will point out a often overlooked flaw with the Sprinter van. It isn't 4wd.

For driving on improved roads, the Sprinter is great.

Mercedes started selling a 4wd version in 2015, which is is being sold at a ~$7,000 premium to the 2wd version.  While a 4wd Sprinter is pretty much ideal for my purpose, it is very expensive compared to other options.  To buy a new Sprinter 4wd at MSRP would cost me ~$54,000.  I am still mulling over more cost efficient options, such as a 2wd Ford Transit or a Toyota Tacoma + slide in camper to be more cost efficient. 

What you are proposing can be done, and available solar power *shouldn't* be the limiting factor.

You can use 3 SunPower e327 panels. (Or the X335/X345 panels) They are 5 foot long, and 41" wide. There will be about a ~14inch gap for the vent.

How do you actually buy the high-efficiency residential solar panels?  It appears that SunPower and other high end manufacturers try to force you to buy a turnkey package from a certified installer, rather than allowing you purchase them yourself and perform a DIY installation. 

Your detailed recommendations and advice are awesome and much appreciated.  I would definitely prefer to use the recommended 3 SunPower e327 panels, if I can figure out a way to install them at a reasonable price.



GuitarBrian

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #27 on: December 11, 2016, 10:06:17 AM »
I was able to buy the panels through a dealer. He had a couple that had been installed, and then removed. Paid $180 on up to $500.

You can also buy the cells individually on eBay, and build your own. Fairly extreme DIY project though:) But, in theory you could do higher density of cells, and more power (except you will loose at least 5% due to the glass and epoxy not being as good as the factory) not sure you could make that up...

I did just run into an issues with no sun for a week. It was tough, basically no solar power (less than
10% of capacity vs around 50) for days. Had to start the truck one night and idle it for an hour or so. Not a big deal, but... Running a refrigerator would have compounded the problem A LOT. If the 12v refrigerator system I am use to in any indication, then I would have been running the motor at least that every day. The alternator charges at a higher rate vs. a generator, so using a generator would have been a couple hours a day. Not a big deal really... Unless it goes on for months.

If you have any questions, I will be watching this thread.

Cottonswab

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #28 on: December 11, 2016, 10:01:36 PM »
I was able to buy the panels through a dealer. He had a couple that had been installed, and then removed. Paid $180 on up to $500.

You can also buy the cells individually on eBay, and build your own. Fairly extreme DIY project though:) But, in theory you could do higher density of cells, and more power (except you will loose at least 5% due to the glass and epoxy not being as good as the factory) not sure you could make that up...

I did just run into an issues with no sun for a week. It was tough, basically no solar power (less than
10% of capacity vs around 50) for days. Had to start the truck one night and idle it for an hour or so. Not a big deal, but... Running a refrigerator would have compounded the problem A LOT. If the 12v refrigerator system I am use to in any indication, then I would have been running the motor at least that every day. The alternator charges at a higher rate vs. a generator, so using a generator would have been a couple hours a day. Not a big deal really... Unless it goes on for months.

If you have any questions, I will be watching this thread.

Thanks for the advice! 

Just curious, is installing the SunPower / residential solar panels yourself significantly more difficult than installing solar panels marketed for RVs (i.e., Renogy)?

Thanks for comparison between the alternator and the generator.  I would definitely prefer to avoid buying a generator and using up precious space.  My strategy is to start-off with just the solar -panels and alternator, and then only consider adding additional items after a few months of experience. 

Syonyk

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #29 on: December 11, 2016, 10:21:07 PM »
Residential panels tend to be fairly large, and I'm not entirely sure how they'd handle the sustained beating of road use.
My random project blog - ebikes, DIY, fans, and more: http://syonyk.blogspot.com

GuitarBrian

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #30 on: December 14, 2016, 01:35:04 PM »
I actually have a Renogy panel on our boat. A big 305w behemoth. The build quality is significantly lower than the SunPower.

It is poly vs mono and the frame is weaker. It is OK, doesn't flex ect. So I don't feel it was poorly built. It just isn't as solid as the SunPower I have in the states.

Both are mounted similarly (fastened along the the two longer ends) and I am able to stand on them in the middle. When doing that, there is more flexing with the Renogy.

The benefit of installing large grid-tie panels, is the price per watt. I found them much cheaper vs 12v panels. YMMV

atoine

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #31 on: February 10, 2017, 12:48:34 PM »
Have you figured your electrical system yet?

To answer your "new" questions:

1- Lithium technology is more mature then ever, but the price is still very high. AGM is still the way to go, unless you have a very high budget.
2- 12V! Most car and camper appliances are 12V. The conversion from a voltage to another is inefficient, so it's better to avoid it. For example, get a 12V battery along with 12V refrigerator, 12V laptop (get a car adapter), 12V fan, 12V LEDs, etc.
3- Blue sea is a very reputable company. Look for "blue sea acr".
4- Rigid is MUCH more durable and also more efficient. Why? Solar panels are sensible to heat; if you stick a flexible panel to the roof, it will get hot and efficiency is reduced. Make sure there is a gap between the roof/panel.
5- If you're still looking for answer, you might want to check this:

http://faroutride.com/ford-transit-camper-van/conversion-planning/electrical-system/

All the details about the Ford Transit cargo van conversion (step-by-step) are filed here:
http://faroutride.com/ford-transit-camper-van/build-journal/

The build is still in progress, but it starts to look like a home :)



Good luck,
antoine
« Last Edit: February 10, 2017, 12:51:19 PM by atoine »

zolotiyeruki

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #32 on: February 12, 2017, 06:26:50 PM »
2- 12V! Most car and camper appliances are 12V. The conversion from a voltage to another is inefficient, so it's better to avoid it. For example, get a 12V battery along with 12V refrigerator, 12V laptop (get a car adapter), 12V fan, 12V LEDs, etc.
One correction here:  although conversion to another voltage is never lossless, it *can* be very efficient (>90%) if you get the right equipment.

atoine

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #33 on: February 12, 2017, 06:38:10 PM »
One correction here:  although conversion to another voltage is never lossless, it *can* be very efficient (>90%) if you get the right equipment.
[/quote]

I agree. But 10% is still "too" much loss when you're off the grid and access to power is limited (solar). So if i can improve my electrical system to avoid that loss, i will. That being said, we do have a 1000W inverter; we just try to minimize the use of it.

Cheers!

zolotiyeruki

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #34 on: February 12, 2017, 07:05:00 PM »
Quote
One correction here:  although conversion to another voltage is never lossless, it *can* be very efficient (>90%) if you get the right equipment.

I agree. But 10% is still "too" much loss when you're off the grid and access to power is limited (solar). So if i can improve my electrical system to avoid that loss, i will. That being said, we do have a 1000W inverter; we just try to minimize the use of it.

Cheers!
When I say >90%, that's putting it conservatively.  If you get a well-designed boost converter, it can be in the upper 90's.  Generally, stuff that runs off higher voltages will be more efficient.  But it's probably not worth it (efficiency-wise) to boost 12V up to 24V so you can run 24V gear.  Better to have a setup that's 24V all the way from panel to batteries to consumers.

LulaNord

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Re: Cargo Van Conversion To Camper Van - Electrical systems
« Reply #35 on: March 10, 2017, 12:01:40 PM »
Hi...i am a new user here. As per my knowledge Solar panels and batteries are DC.  Also, they're limited in their storage and output.  Any time you convert from DC to AC or back, there are losses, usually at least 20%.  So the more you can keep everything DC, the better.  I'd run 12V LED lighting throughout.  I'd use DC fans, get a 12VDC fridge, use buck converters (which can be *very* efficient) to get 5VDC from 12VDC for the usb-powered stuff, and get a car adapter for your laptop that simply boosts the car's 12V up to whatever DC voltage your laptop takes.