What do you need to run a 1800w oven?

[John61CT]

> I do like to keep appliances A/C if I can help it.

But electricity is the most constrained energy store, requires very heavy expensive storage and in many contexts very difficult to satisfy the harsh reality that you need to put back in every cycle more AH than you consume.

And AC is by definition very wasteful of DC energy. Not just the cost of inverters, and their 10-30% ongoing inefficiencies, they draw power just sitting there, have to remember to turn them off.

And utility power is so under-priced, home and RV appliances are never as efficient as those designed for off-grid or marine use.

If you live in something 25+ feet long and don't mind spending thousands on electric infrastructure, anything is possible.

A smaller van, street-parking in a big city, when we haven't even discussed how your X AH per day is realistically getting recharged, your #1 design constraint will be minimizing electric consumption.

There are propane fridges and lights, but those are much bigger compromises than using it for cooking and heat.

 

[jimindenver]

Somebody told me that you haul a nuclear reactor around with you....?   

Shhhhhhh I have it disguised as a Sportsman 800w generator.

 

[jimindenver]

So of the possibilities, solar is not going to be one of them unless you are willing to tow a cargo trailer for the panels and a big one at that. A modest solar system for the day to day loads and a generator for the heavy lifting might be better. A generator along with the trucks alternator might be enough if you use the oven for a few hours a day. Might as well kill two birds with one stone. There are multiple ways to come to the same end depending on what fits your needs.

Considering that this is a 1800w oven I would suggest larger than a 2000w inverter generator. 2000w is the surge the generator can handle for brief instances, the running wattage is lower. Also the ratings are for sea level and a certain temperature. Add in excess heat or altitude and your generator looses power. I would think a Yamaha 2400 inverter generator would be the smallest I would suggest with the oven in mind. A 3000 series if you wanted to run the oven and charge at the same time.

 

[John61CT]

Alt is only going to help a little unless driving all day.

And maybe I missed OP talking about a truck now, my understanding is this is a van, parking on the streets of a big city.

Even with a genny, can't get the bank to full without regular access to shore power.

May need to get a PSOC resistant batt like Firefly Oasis, at $500 per 100AH cheaper than LFP and as lead less risky.

Or just replace cheap GCs every couple years.

 

[jimindenver]

Lithium should be big with the generator charging crowd once the tech matures and prices come down. Just having the ability to not have to have them get to 100% would mean not having to get a spot with electric every few weeks to avoid progressive capacity loss. Being a part timer when I set my system up I did not consider them because the saolar would try to get them up to 100% with full sun in the storage lot. They would have also seen anywhere from -20 to 105 F which may not go over too well.

 

[John61CT]

Yes just accidentally trying to charge them at 10 below will pretty quickly turn the bank into a block of very expensive hazardous scrap.

Which is why no one actually recommends average users try to DIY, but should buy proprietary packaged systems with all the protective electronics built in.

Which is when it costs 10x even high quality lead.

 

[John61CT]

The price of the bare LFO cells IMO won't go down as they get more widespread, maybe on shipping.

But open-hardware BMS will help more ordinary DIYers give them a go.

 

[Spaceman Spiff]

The price of the bare LFO cells IMO won't go down as they get more widespread . . .

I agree.  The price of any lithium battery is going to be volatile for the foreseeable future as demand outstrips supply:

http://euanmearns.com/lithium-reserves-use-future-demand-and-price/

 

[Surly Biker]

Not sure if the OP got his answers, but I wanted to share some personal experience using a 1300W Panasonic toaster oven in my van. I have 630W solar panels feeding a 320 Ah Lithium battery. This system is exclusively solar, no alternator or generator connection. I also have a 1200W inverter, so my system is underpowered to support even a 1300W unit.

An earlier poster noted that these ovens run at full power, but cycle on/off to maintain temperature. I can and do use my oven (I love it!), but I need to apply power carefully by starting at a lower temperature, and easing it up to something in the 350F range. If I turn it on to medium or high at start up, it'll trip my inverter. I find a 20 minute meal at about 80 A current (1000W) is about 25Ah of energy use which is reasonable. I use it to make awesome scones, cakes, muffins, sandwiches, etc.

You can run a toaster oven on a solar system, I do it every day, but as other noted there's high upfront costs. So the OP could look for lower wattage unit, but you need Lithium battery to deliver that high current even for a short cooking cycle.

 

[John61CT]

Thanks for the details there!

I find a 20 minute meal at about 80 A current (1000W) is about 25Ah of energy use which is reasonable

That is one long piece of string there!

Please give a ballpark estimate of your system's total cost for some perspective.

Note an efficient compressor fridge in moderate weather will often burn much less than that **per 24 hours**, and for most setups, that would be a relatively heavy consumer.

If this is in a small van, mostly parked, in a big shady city, without access to plugging the House bank into shore power, the only other option I can see is a genny.

OP, please confirm these details about your use case?

 

[tx2sturgis]

Great information on solar-powered cooking with a toaster oven...real world numbers.

But also, how many times per day can you do that, and in what sort of weather and cloudy days can it be done reliably...and if you cook for 20 minutes after sundown, what is your approximate time the next day when the bank shows back to full charge?

Plus, a 320 ah lithium deep cycle battery wont be  cheap!

And, the OP's 1800 watt oven run off an inverter could approach 130 to 150 amp current draw at 12 volts from the batteries.....which is a lot more than about 80.

I suspect your inverter is very tolerant of sagging input voltage.

 

[John61CT]

A good quality inverter like Magnum, in that size is well over $1500 alone.

 

[Surly Biker]

I find that I need 80-100 Ah per day of solar to get back up to full charge. That is using electric induction cooktop and electric oven, fridge, lights, etc. When conditions are shady or cloudy, I have butane stove and can adjust my lifestyle, but that has only happened a few times this year. I'm in Utah now, and will continue drifting south during the next few weeks as we approach the solstice.

The big issue is the AMPS as an earlier poster noted. 1800W is 150A! Lead batteries can't handle tha discharge rate. Get the smallest oven possible.

My experience desert camping is there is generally enough sunshine, but its cold in the morning. One nice thing about the oven is that all the waste heat warms the van. I definitely wouldn't do anything to try to insulate the stove. My usual program is to make scones or muffins for breakfast and warm up the van .....

If you have shore power or a generator all of this is moot.

 

[kllcbosmetris]

The big issue is the AMPS as an earlier poster noted. 1800W is 150A! Lead batteries can't handle that discharge rate. Get the smallest oven possible.

I checked. Interestingly, even the smallest mini-ovens on that line (smallest version of the one I got, for example) with less functions run on 1800w. Surprising. U.K. campervans have a similar Dometic mini-oven that run on DC but I don't see it in the U.S. Have no idea how much that is. The only oven option I've seen here in the U.S. is Dometic and it is as large of the apartment oven. No go for me.

 

[Surly Biker]

Yeah, what we are talking about are portable table top toaster ovens, not kitchen appliances. My Panasonic is 1300W, the dimensions are slightly larger than one foot in each dimension.

My system limitation happens to be my 1200W inverter, if I upgraded to a 2000W inverter, I could make PERFECT toast!

Honestly, the most cost effective solution would simply be to run a generator for a half hour while you bake your pizza.

 

[Weight]

I would have a difficult time mounting 630 watts of solar to my van. Portable panels to set out when parked would be a pain to wrangle.

 

[tx2sturgis]

My system limitation happens to be my 1200W inverter, if I upgraded to  a 2000W inverter, I could make PERFECT toast!

Honestly, the most cost effective solution would simply be to run a generator for a half hour while you bake your pizza.

Yep, it comes down to cost, every time. What are we willing to pay, to get what we want.

If money was no object we can do quite a lot, but in reality, I often have to settle for canned soup heated over a small propane burner....