Too much or too little Solar?

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GrantRobertson

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Matt71 said:
Do you have a recommendation for a low powered Microwave?

The trick is to get one that has no electronic controls or clock. Those have significant phantom power draws. Look for one that just has knobs for the timer and maybe for the power setting. Other than that, a microwave is going to use however much power is required to heat the food. If you had a 500W microwave it would take twice as long to heat food as a 1000W microwave, so you use exactly the same amount of power in the end.

If you are going to cook with electric, then a microwave is definitely the most efficient way to do that. It has very little wasted heat/energy. This is important if you are in a hot climate and you are trying to keep heat OUT of your living space. However, if you are in a cold climate and need to heat your living space anyway, then you would probably want to use propane to heat your food. The "waste" heat just goes into your space and there is then that much less other heat you have to provide to heat your space.

Even in a cold climate, you don't want to use other forms of electric appliances to heat your food because they draw way too much from your batteries. Sure, the waste heat goes to heat your space, but propane (or some other burned fuel) would be far, FAR more cost effective, and boondock appropriate for that.

As to where to find a "manual" microwave: You are just going to have to look around. I am sure RV dealers have them but they are probably expensive. I have seen them sold for use in office break-rooms because they tend to be more reliable. I found one just by going around to every department and appliance store in LA, back when I lived there. I really had to look around a lot, but that was pre-internet.
 

Matt71

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We'll be following the warmer weather so we're not expecting to have to deal with the cold very often. I think the lowest temp we'll hit where we will be sleeping in the van will be above freezing and that will just be at night where we'll be under the covers. Plus we'll have a propane heater for those times. We're looking at THIS one, but it may be bigger than we need.
 

akrvbob

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Matt, I think you're trying to take the comfort level you had in a house into your mobile life and that's tough to do for a boondocker.

Many of you're big draws can be replaced by smaller draws and other things can be simply left out. a big one would be to get a 12 volt compressor fridge that draws very little power like an ARB Engle, Dometic or Whytner. They are expensive but they will pay for themselves in not buying ice.

Here's my suggestion if you can afford it: 400 watts solar, 4 golf carts, Honda or Yamaha 2000 generator, good quality battery charger like an iota.

The generator run run your imac, the microwave, a small AC and charge your batteries in bad weather. It solves all your problems. Since the iMac is part of your job and how you will make a living, you can't really get rid of it anymore than a camera or lens.

But, you still need to adapt a much more conservative attitude towards power and rethink how you are living. I think you will find your renewed connection with nature will solve a lot of your desires for entertainment.

You have a great overall plan and I think you are in for the best times of your life!! You can do it!!
Bob
 

akrvbob

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The common confusion with amp readings is that when a 110 volt appliance is connected to an inverter and drawing from the battery, you divide by 12 and not 110. A 360 watt draw on the iMac divided by 12 volt is 30 amps. Plus at least 10% waste by the inverter so it's probably even more. Pure Sine waves are even less efficient so it's probably closer to 35 amps.

Bob
 

akrvbob

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The common confusion with amp readings is that when a 110 volt appliance is connected to an inverter and drawing from the battery, you divide by 12 and not 110. A 360 watt draw on the iMac divided by 12 volt is 30 amps. Plus at least 10% waste by the inverter so it's probably even more. Pure Sine waves are even less efficient (they work harder to make cleaner power) so it's probably closer to 35 amps.

Bob
 

Bdog1

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Am I correct this is just for one trip? Way cheaper to stay in campgrounds than try provide all your luxury on board.

Solar and inverter/genny is thousands. The areas you mention are not overly expensive to camp. $24 a night maybe? Camp for two nights and boondock for two, you could get by with one extra battery, charged from the car. $100.
 

Matt71

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We're going on a 7 month trip at which point we'll decide if it's something we want to continue.
Here is the current itinerary
 

TucsonAZ

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I didn't read all of this but saw you have a $1,200 budget which can get A LOT done! If you're going with a MPPT charge controller use grid tie panels, should be a huge savings, I would say at least 40% on the panels.

Also, search craigs for "AGM", I got my 100+ ah batteries like that for $60 each and they're kicking ass! They're old system pulls, not "ideal" for solar but better than a marine battery or anything like that.

$1,200 iS healthy budget, shop around as that should get you 600-750 watts of solar, a CC, and some good battery storage.

The crock pot isn't gonna happen!
 

gypsychic

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Instead of a crock pot use a wonderbag. Personally I think they are high priced for what they are and I'm in the process of making a DIY version, but I have more time than money so YMMV. Here is Bob's blog post about it. There are also many YT vids about wonderbag cooking or off-grid cooking. I've researched it for home cooking to reduce my utility bills. The knowledge has come in handy as I plan to transition to a van.
 

Almost There

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gypsychic said:
Instead of a crock pot use a wonderbag. Personally I think they are high priced for what they are and I'm in the process of making a DIY version, but I have more time than money so YMMV. Here is Bob's blog post about it. There are also many YT vids about wonderbag cooking or off-grid cooking. I've researched it for home cooking to reduce my utility bills. The knowledge has come in handy as I plan to transition to a van.

Oh so many thanks for finding the DIY instructions. I'd looked at Bob's blog and the Amazon link and thought 'how wonderful, but I'm not paying THAT kind of money for it'.

DIY I can do!! And now I don't have to re-invent the wheel.
 

gypsychic

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Sorry OP for a quick diversion from your main topic:
Almost There said:
Oh so many thanks for finding the DIY instructions. I'd looked at Bob's blog and the Amazon link and thought 'how wonderful, but I'm not paying THAT kind of money for it'.

DIY I can do!! And now I don't have to re-invent the wheel.

No problem. I'm sure with your sewing skills it will be easy for you. I need to dust my skills off but that will be good for me. I know I could make this for a fraction of the cost they charge. It's actually quite ridiculously expensive. I've thought of possibly making some to sell, as I could probably charge half what they are and still make a decent profit.

Anyways, I am going to also add reflectix-type to mine to see if it makes an improvement in the overall size of it. The DIY version also has an update for a pan with a long handle so you can really customize the version you make for the pan you will use most often.

I was planning on taking pictures and posting a thread of it when I get around to it. If you make it first, perhaps you could make a thread. Cheers

Now back to the original thread... :)
 

akrvbob

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No doubt, they are way over-priced, but bear in mind, for every one they sell, they send one to Africa for free, so you are buying two even if you only get one.

They are also very well insulated. I don't know what it is, but it's a lot better than just some bating thrown in.
even so, i carry a down-alternative comforter for the coldest nights and my guess is I could just wrap the pot up in it really well and it would do as good or better job and I already have the comforter.
Bob
 

Almost There

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akrvbob said:
No doubt, they are way over-priced, but bear in mind, for every one they sell, they send one to Africa for free, so you are buying two even if you only get one.

They are also very well insulated. I don't know what it is, but it's a lot better than just some bating thrown in.
even so, i carry a down-alternative comforter for the coldest nights and my guess is I could just wrap the pot up in it really well and it would do as good or better job and I already have the comforter.
Bob

Oh, it's not that I doubt that it's reasonably priced...I know the value of labor in sewn products - I used to struggle to price my own products at a price high enough to make it worthwhile at the same time as presenting a product that the consumer would buy.

When you can make your own, it's hard to cut loose with the bucks for someone elses' product especially for something like this where I would want it to be color co-ordinated and fit MY pots...:D
 

Matt71

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I think I'm going to try to sell my iMac and replace it with a refurbished 17" MacBook Pro. It only draws 7Amps compared to the 30mps the iMac draws. If we cut the 12V cooler idea and limit our DVD viewing to when we have hookups (which will be 90% of the time) we can get under 200Amps a day


Gold Stars GW21500 RV Reading Lights (x3)    0.78A @ 5hrs = 3.9A
Roadpro 12 volt oven                                       12A @ 1hr = 12A
A MacbookPro w/ 85W Adapter                          7A @ 4hrs = 28A
Laptop                                                           12A @ 4hrs = 48A
cPap                                                               6A @ 7hrs = 42A
Fan                                                                 3A @ 10hrs = 30A
Westinghouse WCM660W 600W Microwave        50A @ 0.5hrs = 25A

,Matt
 

jimindenver

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200 Ah a day is four grp 29 batteries, four 6 volt golf cart batteries or two of my huge 8-D batteries. You will need 400-500w of solar to keep them happy day to day and cover any shortfall with a generator and decent three stage charger or you simply wont have power to get through another day.

Since you are going to have to have a generator anyways, why not cut back on the battery and use the generator to run the microwave and computers while you charge. I can run a 900w microwave off my 8-D for 3 one minute runs but it's wicked on the battery. I can run it for ten minutes with 490 watts of solar boosting it but after that I have to stop running it and let the solar bring the battery back up. Take it down too far and it just wont be coming back up at all. You are still going to need at least two batteries to cover a day and 200 watts of solar.
 

akrvbob

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The 600 watts on the microwave is output power, not input power. With the 700 watt micro they draw about 1200 watts which works out to be 2 amps per minute. Your 30 minute cook would draw 60 amps.

30 minutes on a microwave is a lot,, is that over the whole day?
Bob
 

Matt71

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I rounded up for the whole day figuring at most 5 minutes per person per use.
Doubt we'd ever use it that much on a regular basis.
 

akrvbob

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I have 570 watts and 6 golf carts and I can pretty much use everything I want during the day and be a little more cautious at night. Even in the winter. I only use my micro for maybe 5-10 minutes a day and it has no impact on my power.

I have a friend with 500 watts and he uses an induction cook-top and he figures about 10 minutes and 20 ah a day. Again, no big deal at all.

You can figure 2 amps a minute for either and you need a 2000 watt Pure sine wave inverter.
Bob
 

Matt71

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Was planning on the Pure sine wave inverter because my strobe lights require one if I ever use the van power for them. Thought I'd be able to get by with a 1000 watt one, but I guess not. At this rate, the guts of the van are going to cost more than the van itself. This cheap RV living is getting expensive. LOL
 

Matt71

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Just took a look at our itinerary and the bulk of the time we will be without hook-up power will her at national parks.
Yellowstone - only select (more expensive) campgrounds allow generators
Yosemite - restricts generator use to 2 hour blocks throughout the day
Glacier National Park - restricts generator use to 2 hour blocks throughout the day
Grand Tetons - only the RV parks allow generators and they cost twice as much
Big Bend National Park - No Generators

I'm wondering now if it's even cost effective to invest in the solar and a generator. Right now I'm looking at $1700 for 400W solar, two 125A batteries, 2000 Watt inverter and 30 Amp Power Controller. Then another $600 to $1000 for a generator.
 
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