DC Electric Water Heater with Heat Exchanger

12V (or110V)Seems like a lot of headache to me. Why not use a small Camp Chief tankless water heater and propane? The tankless uses two "D" batteries for ignition.IMG_1602.JPGIMG_1080.JPGIMG_1063.JPGIMG_1606.JPG
 

RAM5500 CAMPERTHING

OG Portal Member #183

john61ct

Adventurer
Using stored or off-grid electricity for any usage involving heat production

is much more expensive and complex than just burning fuel directly.

Thousands of full-timers get by just fine on less than 20-30Ah per day of electricity.

People trying to duplicate the USian S&B dwelling lifestyle in a mobile context mostly end up in serviced campgrounds, or carrying around a generator and its fuel.

Not saying one set of choices is "better" than the other, but noobs often just don't understand just how energy frugal a "tread lightly on this earth" travel lifestyle really is.
 
Hardwiring something into already existing electrical system sounds like a lot of headache to you and instead you’d rather add additional gas sources and batteries??

Ummmmmmm
Just my opinion.. My tankless has/propane has proven robust. Batteries? 2 "D" cell duracells for ignition built into the heater. Propane? doesnt everybody have that for a stove anyway. It just how I choose to do it. And yes I have 640 watts of panel and 2D storage battery supplying a 2000 watt converter so ya I thought about an electric heater as well.
 

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Using stored or off-grid electricity for any usage involving heat production

is much more expensive and complex than just burning fuel directly.

Thousands of full-timers get by just fine on less than 20-30Ah per day of electricity.

People trying to duplicate the USian S&B dwelling lifestyle in a mobile context mostly end up in serviced campgrounds, or carrying around a generator and its fuel.

Not saying one set of choices is "better" than the other, but noobs often just don't understand just how energy frugal a "tread lightly on this earth" travel lifestyle really is.
And a tankless water heater is less than 300 dollars...
 

Peter_n_Margaret

Adventurer
Propane? doesnt everybody have that for a stove anyway.
No.
With the low cost of solar and the advent of Li batteries it is quite viable to have no propane or butane and go all electric and diesel.
We are part way there, others are well in front of us with this transition.
Hot water and central heating are diesel or engine waste heat. At times of plenty of sun, hot water can be electric (1,000W immersion element in 22L storage tank). Fridge and freezer are compressor. Our cooking is still propane, but the usage is down to about 1kg per month full time on the road.
The next step is to get rid of the gas and go induction cook top via solar and inverter.
Cheers,
Peter
OKA196 motorhome
 

RAM5500 CAMPERTHING

OG Portal Member #183
No.
With the low cost of solar and the advent of Li batteries it is quite viable to have no propane or butane and go all electric and diesel.
We are part way there, others are well in front of us with this transition.
Hot water and central heating are diesel or engine waste heat. At times of plenty of sun, hot water can be electric (1,000W immersion element in 22L storage tank). Fridge and freezer are compressor. Our cooking is still propane, but the usage is down to about 1kg per month full time on the road.
The next step is to get rid of the gas and go induction cook top via solar and inverter.
Cheers,
Peter
OKA196 motorhome
Exactly! I agree 100%

Im fully solar and electric everything except for the furnace, which is plumbed right to my fuel tank.
 

danneskjold

Active member
I have a Kuuma 6gal water heater that is primarily "powered" via engine coolant, but can also be plugged into 120v if you're not driving that day.

I have 945W of solar, and 300ah of lithium batteries (at 12v). The heating element uses 1500W of power (typically takes 30 minutes or so to heat up), my system can definitely handle the load *during peak solar production* but any other time it's definitely too much for my system. Adding in another 100-200ah of lithium would go a long ways towards allowing the system to handle the load.

One additional benefit of this vs a propane "tank less" system is it uses a lot less water.
 

RAM5500 CAMPERTHING

OG Portal Member #183
There's some flawed, and straight up wrong information in this post.

It most definitely can be done, and easily at that.

This is a pay to play type of thing. Good things don't come cheap.

I won't argue paper specs on here, like so many seem to love to argue about, but i will argue real world stuff all day long...

2 different friends have the Isotemp Slim Square water heater which had a 115v 750watt element and a 4 gallon tank in their rigs.

These are standard equipment on the Global Expedition Vehicles, and many yachts. Both of them said, just with the heating element, and not the hydronics running through it, they have the 4 gallons heated up for a hot shower in 30-40 mins.

Math: 65amps +/- at 12v (6.52 at 115v) for 30 mins is a total of around a 32amps +/- draw (12v). Correct me if i'm wrong.

This is almost a non-issue for anyone with a decent size battery bank. Personally, i have 1 300ah lithium right now, and on the fence if i am adding a second.

I have 750 watts of solar and a 150/70 controller and a 60amp Sterling DCDC. If 100% cloud cover, and zero solar input, i could top off the battery easily idling it for a short time. But doubtful i ever would need to, but the option is there.

Its pricey ($800-ish) but its low (relative) draw and dimensions, make it ideal for a lot of applications if ya have the $ and deem it worth it for your application.

For me, the math, dimensions, and draw make sense to invest that much $ in a water heater that will take up very little space and has an excellent reputation and been around for years.

Some my say its too expensive. I've learned YEARS ago, an ounce of prevention saves a pound of headache, cry once...
 

RAM5500 CAMPERTHING

OG Portal Member #183
Propane? doesnt everybody have that for a stove anyway.
Not anymore really... With the advances in solar efficiency, affordability, and the ability to draw lithiums down really low without damaging them, more and more folks are going with induction cook stops and getting rid of propane all together.

My last camper (Brand new 2018 FWC Hawk) used propane, and it gave me nothing buy headaches, to the point, i am spending a lot more money on this build to completely eliminate it all.

Propane is also a pretty crappy fuel for heaters if you have a soft top and camp in cold weather. Loads of condensation. Diesel heat is completely dry.
 

Cthayn

Member
I will add my input to this discussion.

Our campervan is all electric, with exception of the Webasto header and V10 engine, which both run off the fuel tank.

The specs are 400 W of solar feeding 200 kWh of lithium batteries, along with the alternator charging when we drive. With this set up we cook with an InstaPot, microwave and induction cooktop. We also have adequate hot water from the 2.5 gal water heater. The heater is a 110V heater from Home Depot with the heating element replaced with a 12V, 300 W heating element. The system is designed to divert the excessive solar power (after the batteries are charged) to the hot water heater. The hot water system cost about $250. The solar/battery system cost substantially more.

Here is a link to the build thread. The hot water system starts on post #133.

https://www.sportsmobileforum.com/forums/f24/2012-e-350-eb-v10-4x4-ccv-top-20698-14.html

We have over 150 nights in the van and we have never ran out of hot water. We have adequate hot water to wash up and clean the dishes each day and both take a shower at night, if we want to. If we get some sun during the day, the battery is topped off and the water is heated. Now, if the day was overcast or we camped in total shade, the battery power would only last a day or two, depending how we conserved power while cooking. Usually we drive most days, so we have never lacked in battery power or hot water.

>> Corey
 

john61ct

Adventurer
The limiting factor is roof space for the solar.

400W is just not near enough for a full electric galley freezer, computers stereo **plus** HWS and forget about space heat or aircon.

obviously in cold temps the top priority is a sealed envelope, only controlled ventilation, and thick insulation

no matter your fuel source.

Coming up with a use for excess solar is fine but again, rarely enough energy for more than pre-heating your shower water a bit

often not worth the extra cost and complexity from an economic POV.

Just learn the Ah per 24 draw if a given load, empirically not spitballing

so you can be realistic in planning with a systemic approach.

Every noob starts out with grossly optimistic ideas.

Nothing wrong with starting out with a genset if you "really need" high consuming devices

then use solar to reduce your runtime and fuel costs.

But if you want a true "mostly solar" off grid living setup, put in lots of extra time planning and invest in lowering your Ah per day consumption

much higher ROI than trying for high Ah per day production.

Once you've committed to thirsty consumers the low-impact game is over, much easier cheaper and sensible to start small and slowly scale up later when schmarter
 

shirk

Active member
Part of the discussion needs to be are you boondocking or are you constantly moving? If you plan to set up out in a single spot for 2 weeks at a time you're going to need serious solar to go full electric. If you plan to move every 2-3 days you'll be able to recharge off your alternator.

This is in french so run it through google translate.


His small build is an interesting take on going full electric, 320 ah lithium with induction cook top, microwave, and electric hot water. No solar. He's got enough battery bank to cover a few days of use and an hour of driving adds one day's worth of power back into the bank from the alternator.
 

john61ct

Adventurer
Yes LFP is what makes that scenario more practical, the chemistry high CAR and no need to get to Full

Carrying an inverter genset another FF alternative if you're not driving much every week.
 
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