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Discussion Starter #21
There’s more to sizing the system than just adding up loads. We’ve never had our 200Ah batteries down to 50%, probably below 60% less than a dozen times in 5 years. Yet when these batteries die, I will upgrade to 300Ah and I look forward to the day. Why? Draw-down voltage.

We use our 700W MW (1100W draw) every day. There is also the high-draw Instapot. When the batteries get down to 75% or so, the inverter can get unhappy when these heavy draws pull the voltage down. (800W water boiler and Sous Vide are not as much a problem.)

Seriously consider the Sous Vide for heating water. Do the heating when you have solar, alternator or shore power. Use the water when you want. No mixing, no wasted water, no plumbing. If 105° shower feels good, heat to 105°, or a bit more if it’s going to be a while.

See my build blog for details.
Thanks for the feedback.

"There’s more to sizing the system than just adding up loads. We’ve never had our 200Ah batteries down to 50%..."
are you implying that once I have added up my loads I should double it, to figure out what size battery I need so that it's never down to 50%?

I'm googleing the Sous Vide now, thank you
 

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You wouldn’t be really messing with the engine. You cut a T into the coolant line from the radiator then run your pipe (hose) to the heater in the van then run another coolant line back to the radiator return. At the heater (in your living space you run a fresh water line from your water supply (tank) to the heater and then out to your faucet, shower, etc. not very high tech!
The diesel parking heater isn’t even connected to the engine. You simply mount a smalL 5L fuel tank beside the brake fluid reservoir and a line to the parking heater - bing, bang, thank you man🤭
 

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Discussion Starter #23
You wouldn’t be really messing with the engine. You cut a T into the coolant line from the radiator then run your pipe (hose) to the heater in the van then run another coolant line back to the radiator return. At the heater (in your living space you run a fresh water line from your water supply (tank) to the heater and then out to your faucet, shower, etc. not very high tech!
The diesel parking heater isn’t even connected to the engine. You simply mount a smalL 5L fuel tank beside the brake fluid reservoir and a line to the parking heater - bing, bang, thank you man🤭
hmmm. I was told that if you touch/play with/alter the engines in your vehicles, in any way, the warranty would be compromised and no longer applicable. Do you know if doing something like this would affect the 6yr 100,000mile warranty I have on the van?
 

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I can’t give you a definitive answer on that, unfortunately, but Ram sells a rear heater installation kit that does exactly what you need & want. Instead of connecting a heater to it you would simply connect a hot water heater to it - basically the same thing. You may be able to get a dealer to recommend a certified upfitter to do it for you but they ain’t cheap. You might be able to get the dealer to install the kit. Everyone and every dealer will probably give you conflicting information however.
 

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The marine heaters are super efficient and some have a less efficient 120v element also. Electric heating is not efficient. Heat is a byproduct of electricity, not it's intended effect. The sous vide (its really for cooking and heats slow and easy, plus sidepoint: great steaks with no effort) is probably the next best thing if not wanting gas. It's about the same total watt draw(energy required to heat is energy required to heat), but more gentle on the batteries.
Really should try to avoid running anything much over 1000w on a 12v bank. It's tough on the batteries unless the bank is huge and then still the amperage is kind of extreme and wires should be pretty thick.
2000w+ inverters should really be run off at least 24v, which is just as easy if you're using a large bank, however, it uses different equipment. The wire can be smaller also since the voltage is higher and amps are lower.
If you're really thinking 300ah in lithium, you shouldn't have all that much issue - but, that's a huge price tag to power a $129 water heater.

I talk too much, but something I haven't seen suggested yet - especially since you're chasing warm weather - is just some black paint and sunlight. Everything else on your list works fine on a smaller battery setup.
Go with a solar shower, maybe a sous vide or electric kettle or pot on the stove as backup for nights or grey days.
 

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Thank you for looking at the spreadsheet 💜💜

I doubled the Amp on the Maxx air fan in my chart because I'll have 2 of them. Maybe that's why it seems high to you. If I have two would you still think 5 amp-hrs a day would be correct?

The domestic stove specs were provided in Kw not W. I think it's for the lighter. But I guess I could just use a match to light it myself. To be honest, I'm not sure what the 7200Kw is for, I just found it on their website and added it to my chart. 🤷‍♀️

I plan on chasing warm weather + summer, so I won't need a heating unit for the air, just a heating tank for my water. I've briefly considered getting a propane water heater, but propane scares me frankly so I was trying to avoid it if I could. However, if the amount of energy needed for an electric hot water tank is just not worth it, then I will def consider propane. It'll just mean tackling another scary & unknown part of my build that I was trying to avoid tbh.

I'm not sure if you noticed, but I have a lot of ? in my chart. and that's because I couldn't find any of those specs online. Is it normal to not be able to find specs like these? I don't understand why I'm having such a hard time finding this data to fill out my chart.
Hi,
So, the Dometic stove you linked to is a propane stove, and the 7200 kW output they list is energy the propane is supplying -- the electrical demand of such a stove would be essentially zero. But, the 7200 KW they quote is a screwup on their part -- this would be 24 million BTU/hr, which is ridiculous. They probably mean 7200 BTU, which is what it says at the top of the same page for burner output.

If you actually want a stove that uses electricity as its energy source, search amazon for "inductive cooktop" -- this will get you some 1 or 2 burner inductive cookers that will work for a camper van.

We have a single MaxFan, and, based on its performance, I wonder if you really need two of them? If we open the windows by the beds a bit and run the fan, the airflow is very good with one fan. But, if you think you really need two of them, then, yes, I'd bump the consumption up a bit.

On the hot water, there are lots of propane RV water heaters like this one: Amazon.com: Suburban - 5117A Water Heaters 6 Gallon: Automotive
These have been used in RV's for decades and are reliable and safe designs.
We agonized over this issue of hot water a bit for our conversion, and decided we could just heat some water in a pot for the washup, and, for us, this has worked out fine.
If you want an electric solution, there are several small RV size electric water heaters, or the sousvide approach works too.

You really need to make the decision on which energy source for cooking and for heating water, as if you go electric on these, they will both be big loads that will the bulk of what sizes your electrical system.

Gary
 

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So would you suggest a gas heater? Sorry I'm not sure I'm understanding what your suggestion is.
Hi smashley

Sorry my recommendations probably got lost in my posts;

1) You should figure out what energy source you want for both heating hot water & heating your van as if you want to do it with “battery” 12v it is very expensive & you will need a more complex electrical system

2) I recommend for “heat” items if 120v is not available via shore power that the fuel to most efficiently do that would be gasoline, diesel, or propane.

Van electrical systems in my opinion are best when kept simple. A simple system can not “heat” things with 12v battery power as a fuel

Electrical designs are created from the assumed loads (the stuff you want). Also it is a good idea to have some “extra room” in the design for changes (increased loads).

In my case, my energy “fuels” are;

12v
for; fridge, lights, usb chargers, roof fan, water pump, fan for propane heater (which was an added load)

120v for; Hot Water Heater (my Honda generator can be connected to the shorepower to provide 120v via gasoline as a backup if boon-docking)

Propane for; interior forced air “heater” for the van & for cooking “heat” outside the van on a 60,000 BTU single burner
 

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I plan on chasing warm weather + summer, so I won't need a heating unit for the air ...
We thought the same thing at first, but realized we'd also be traveling through cooler climes (latitude and elevation) on our way to/from warmer places. During our Arizona trip last fall, it was already too cold to camp north of Sedona, and it was cold on the way back home to BC. I have since installed a parking heater, so we have more options now. But we are still resisting adding an A/C unit.
 

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Well that is true, but, in terms of $ it is crazy expensive both in our houses and in our vans- lots of lithium batteries, B to B charger, second alternator, $$ BMS, huge solar, expensive controller etc. It’s fine if you are a sparky trained sort of person and understand what you are getting into money wise. I like the idea of a zero carbon footprint camper but without an electric van that will do 300+ miles and let me recharge in less than an hour to go 600 miles per day I am not there.
 

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Electricity does make heat well, due to it being a byproduct of the usage, but I maintain it does so inefficiently due to the fact that it creates the same heat despite it's intended purpose. If you power 1500w of electronics it will produce the same heat, relatively, as a 1500w heating element.

This is the way high wattage heat lamps work and, conversely, why LEDs do not get as hot as the bulbs they replace. Electric heaters, in essence, "waste" the power that could be utilized for something. The main difference is localization of the heat dissipation.

If one could harness the energy being spent elsewhere for localized heat I would say then it's efficient. This is what the isotherm marine heaters do, only they utilize a different source for their "waste heat".

(Edited for so many typos. Apologies if any still exist)
 

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Wait there is a technical definition of efficiency and misuse is not mentioned. " The ratio of the useful work performed by a machine or in a process to the total energy expended or heat taken in.” It was created in the time of steam engines so that is the reference to heat.
So I think Winston was saying if you expend 1500 watts of electricity you get 1500 Watts of heat=100% If you use some to jiggle the bed and don’t count that as heat then you are talking about a completely different thing. The second law of thermodynamics prevents this conversion of being 100% generally as energy is lost to those sort of jiggles etc. and called entropy.
BTW The Greek symbol Eta “η” is usually used to represent the ratio efficiency.
 

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I was under the impression that utilized energy still creates heat. If utilized for mechanical motion, that motion generates its own heat -either increasing or equalizing any heat expended. Thus the need for heatsinks for sensitive or high draw equipment. Space heaters are pretty much just a heatsink attached to a high draw conductor. Is there a theoretic "perfect usage ratio" where heat is not created? My understanding is that even refrigeration is merely relocating heat using additional heat
 

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You can disregard that. I'm sorry I've dragged this off track into more technical topics.

My suggestion to the OP for limited hot water needs in mostly warm environments would still be a solar setup. This is not as optimal of a full solution if particular temperature water is needed or if colder travels are possible, but covers the basic needs provided
 

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Sure thats the jiggle I included. I get your point that you are expressing I think. There is lots of waste heat to be utilized and an efficient total system finds ways to make it do work instead of loosing it and that is consistant with the definition. I agree to take heat from a running engine who’s efficiency (energy burned/motion of vehicle) is about 20% and capture it in hot water increased the efficiency of the total system. You have to define the system to talk about those things or you begin to say things like “He is an efficient worker” because even though he gets less done than everyone else here I pay him less so I am ahead. Yea I am responsible for the transgression (along with Winston).
 

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But that only works if you drive the van. Sous vide works whenever you get electrons.
The 4 gal. Isotemp (heated by engine coolant) in our van still puts out warm water on the third day after no driving. Yes, if you stay put more than three days often without shore power, it might not be ideal, although it does have a back up electric element, which we've never needed. It's "free" hot water, and even a 15-20 minute drive to a trail head heats it back up. I highly recommend considering it in any van conversion where hot water is wanted.

I suspect a sous vide would work quicker using less electricity if the water was hot from the Isotemp to start with.
 

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Hey lovely people! New here, new to van life, and just starting my build with absolutely no experience at all! I want to start living in my van full-time by October and travel around the US & Mexico. I work Mon-Fri 9am-5pm and plan on always being nearby some sort of co-working space for this reason. (so I may spend more time in cities, excepts weekends)

I have no idea what I'm doing and have SO much to learn. I've been watching lots of youtube, reading a ton of blogs. However, I still feel like I know absolutely nothing when it comes to electrical. I also know that planning the electrical setup is one of the 1st steps in the build phase so I'm feeling very stuck.

I'm trying to get an understanding of what I'll be using that needs power and how much power I anticipate drawing on a daily basis. To ultimately help me understand what size batteries I need, inverter, how much solar panels I need, etc.

Here is a google sheet I created to try and calculate my needs. I'm struggling to find out how much consumption the products I plan on having use. I haven't bought these products yet, so I'm trying to find information online but it's really not helping. Manufacturers' website doesn't seem to be helping me much either.
Can someone take a look at the google sheet, especially the purple text, and let me know if you have any insight or help you can provide me?

Ultimately, the point of the google sheet is to understand:
• what size battery do I need, and how many
• what size inverter do I need
• ideal amount of solar Watts I need
• size of the charge controller
t W
Hey lovely people! New here, new to van life, and just starting my build with absolutely no experience at all! I want to start living in my van full-time by October and travel around the US & Mexico. I work Mon-Fri 9am-5pm and plan on always being nearby some sort of co-working space for this reason. (so I may spend more time in cities, excepts weekends)

I have no idea what I'm doing and have SO much to learn. I've been watching lots of youtube, reading a ton of blogs. However, I still feel like I know absolutely nothing when it comes to electrical. I also know that planning the electrical setup is one of the 1st steps in the build phase so I'm feeling very stuck.

I'm trying to get an understanding of what I'll be using that needs power and how much power I anticipate drawing on a daily basis. To ultimately help me understand what size batteries I need, inverter, how much solar panels I need, etc.

Here is a google sheet I created to try and calculate my needs. I'm struggling to find out how much consumption the products I plan on having use. I haven't bought these products yet, so I'm trying to find information online but it's really not helping. Manufacturers' website doesn't seem to be helping me much either.
Can someone take a look at the google sheet, especially the purple text, and let me know if you have any insight or help you can provide me?

Ultimately, the point of the google sheet is to understand:
• what size battery do I need, and how many
• what size inverter do I need
• ideal amount of solar Watts I need
• size of the charge controller
A good place to go is youtube, I like this guy Will Prowse, he's really good at explaining all of the exact questions you're asking.
 

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That’s about the worst advice anyone could give you. People who go to uTube for help end up more confused and make more unnecessary expensive mistakes and wate more money than if they asked here where the members are more than pleased to give good, honest, real advice.
 
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