Running Water heater on inverter

[LargeMarge]

My water heater is a propane...a 400[W]att 'HotRod' to convert it to electric. I also installed a 1500 [W]att inverter...experiment by running my water heater off the inverter. I can make enough electric to power everything I need, so I am trying to find ways to save on propane usage....[RL]

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We also operate our water heaters through our inverters.
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Our hot-water tank is a three-gallon stainless-steel 'Torpedo' keg, a miniature version of our five-gallon stainless-steel retired Pepsi® kegs.
Our water heaters are 120vac 'sous vide' circulation heaters designed for slow-cooking in the kitchen.
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We decided on simple, redundant, and stand-still house common instead of the usual RecreateVehicle appliances because...
... we delivered RecreateVehicles manufacturer-to-dealer and dealer-to-shows.
A year and a hundred thousand miles convinced us to 'lower our expectations' about factory RecreateVehicles.
But all that probably changed in the years since that gig, because RecreateVehicle customers demanded improvements... right? [the 'sarc' light is lit]
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We think a three-gallon shower on the porch is adequate, although a half-hour standing soak at the gym is pretty darn nice, too.

 

[jimindenver]

So there ya go. Between 600 watts to around 2000 watts of solar panels, and something like 400 ah of battery capacity.

Give or take, about $2000 to maybe $5000 worth of hardware to save a few dollars worth of propane per week.

Yeah, if you already have all that capacity and make use of it in other ways, (cooking, A/C etc) then sure, it will work but buying and installing all of that JUST to have a warm shower every other day is not really practical.

400 watts even flat mounted should be able to provide at least half the power needed to run the Hott Rod during the peak of the day. 300 Ah of Lithium fully charged should easily be able to cover what the panels can't cover for the duration of time needed.

What we don't know is at what time the test was run. What state of charge the batteries were at and what other loads were pulling on the system.

 

[Freelander]

It was working well when the sun was shining. I am also running an ice maker at about 80 watts and my computer at about 55 watts. Plus a fan or 2.

 

[Freelander]

I am looking into this again.

My water heater is using about 360 watts AC to heat it. As of right now my Panels are making about 230 watts DC, and my batteries are charging. The shunt is showing an extra 160 watts DC going into the batteries.

I am also running a counter top ice maker at the same time, it uses about 80 watts AC to make ice, but it cycles on and off. I plan to make ice and bag it up so I have enough to get through the day and night. Plus all my normal loads computer, 12v freezer, lights and fans.

I will keep checking this as the day goes on.

The water heater still had some hot water in it this morning, I think this will work if I shut the inverter off at night. No need to heat water if I'm in bed.

EDIT: It seems to take about 2 hours to heat my water, I will check it again in the morning and time the amount of time it takes. I am basing that of the amount to time the Inverter fan was running.

 

[Calaverasgrande]

I was looking in to this a while ago. Sad that small water heaters for RVs are so expensive!
I found an AC/DC water heater for boats, but it was north of $1000. Because boat stuff is double rational prices.

 

[frater secessus]

On the other hand, there will be no automatic cut-off when the battery gets low.

Would be an exceptional opportunity load:

LVD -> relay -> water heater

 

[Freelander]

After trying it for a second time I have decided to not do that anymore. it drains my batteries to far and it takes to long to recharge them.

I am still on shore power so I can switch back and forth, I spent a good portion of the day getting batteries back to full charge. If I need hot water I will go back to using Propane, and anytime the Generator is running it can heat my water for me.

 

[Freelander]

Last year I was able to charge my batteries to full charge from the solar, but this year I added a 12v Freezer to the RV. And it seems to be pulling around 60 watts I dont know if that is the average or only when it is running. And because of that I can not get my batteries to full charge from my solar. I can get close but not full charge, I will keep checking it over the next few days.


OK I have the freezer over on 110 AC now and it looks like it is only drawing about 38-45 AC watts at the most. Since this freezer will switch automatically from AC to DC I will checking it. That is half what the ice maker draws.

The manual says about 65 watts.


https://www.amazon.com/Whynter-FM-45G-45-Quart-Portable-Refrigerator/dp/B002W8BLUG