microwave ovens on 12V

[Graeme]

Can a microwave oven be used for anything running via a converter in a van? They seem rather useless but perhaps not.

[LandyAndy]

Graeme.
Have you looked into a 3 in 1 controller for your van??? See this thread,the version DSwatts reccomended sounds very good.
http://www.aulro.com/afvb/alternate-energies/225923-combined-solar-controller-inverter-system.html
Andrew

[Graeme]

Thanks Andrew. I was more looking for what uses people find it practical to use a microwave oven in a van but I obviously need to consider their solar capacity at the same time. Our 800W (RF o/p, 1200W i/p) microwave oven would cause an inverter to draw around 120A which would place quite a burden on the battery/batteries if used for other than a short time.

I've noticed a lot of later vans only have a hot-plate and grille, which might or might not be upgradeable to include a gas oven on a van at build time but not so easy if buying s/h. Hence I'm wondering if a micro-wave oven is at least partly a viable alternative.

[AndyG]

How about a 12v oven like the travel buddy

[Pedro_The_Swift]

Gas Oven and gas hotplates and 320Ah and just no.;)

[Blknight.aus]

depends on the size of the panels, batteries and what you're going to do with it.

lets say you have your 400w of panels on the top, in the sun, its lunch, the vehicles hooked up and you're going to stop for a couple of hours, and cook lunch in the microwave. clean up, pack up, go for a walk, play some cards, whatever then drive to that nights camp.

lets say same thing, but you're going to heat seal the leftovers and do something like a quick reheat of it to have it for dinner or for breakfast at say 0900 in the morning after your morning coffee and a quick realign of the panels to get max sun on them.

lets say you're using an 800w microwave and your cooking at the 70% power setting. lets say that your batteries by themselves fully charged can deliver your cooking time *800w

then yes, go nuts you can do that. but its pushing the limits, fine if you're immediately going to drive it and charge it or the panels can deliver enough to charge the batteries and run the fridge during the day.

but get sneaky, try to help it along as much as you can. if you know you want to microwave something wrap it in alfoil and preheat it in the car precook it a little in the engine bay hell put some wool blankets along side to make a heat trap under your solar array and heat it up under there for a while (careful of ants) if its a ground mount setup or if you know you'll be off treking bag it and stick it in the sun in the window of the car with everything closed up.

things with lots of moisture in them microwave up quicker and better, lets say this....

you have a damn good inverter, you have a setup that consists of 4x N70 batteries driving it.. best guess, you could oneshot use your setup for about 30 minutes at 70% without too much hassle and still have enough to run your fridge overnight. with that I reckon I could knock you up a soup, with a stirfry noodle style side, a lasanga , a couple of hot drinks, and a hot pastry dish with a melted chocolate sauce for deserts. for 2.

[Graeme]

How about a 12v oven like the travel buddy
Had not heard of these before but all the reviews can't seem to praise them enough. I want one in the RR - don't worry about the van!

[Graeme]

depends on the size of the panels, batteries and what you're going to do with it....Thanks Dave. Without going through detailed scenarios I suspected that one could get away with using a microwave in quite a few instances and perhaps it would do all we might ever want to.

[TerryO]

An oven is usually a option in just about every make of van if ordering a new one, they usually charge about a thousand dollars extra for a gas oven, bloody rip off as they used to come standard in most vans a few years ago.

We took our microwave out as its a waste of space as even with a reasonable amount of solar and batterys they just run everything flat in about 15 minutes. Re our gas oven, we have used it twice even though we thought we would use it a lot more, the most useful cooking apparatus in a caravan is a Webber Baby-Q BBQ, if you have one of those you use it nearly every day.

The other thing we use if we are doing a lot of driving in a day and don't want to cook when we arrive is a Ecopot. There are lots of different versions of these things, you cook what ever it is you want for about 15 - 20 minutes in the morning and then put it in the Ecopot and when you get to where ever your going between 4 and 7 hours later it's ready to serve up. Good ones come with a small element in them and have a cigarette lighter plug.

[Blknight.aus]

it depends on what you really want to do with it...

realistically...

(and the inverter + the batteries will be your limiting factor)

the best use of a microwave is to save some space in a van thats going to spend most of its life hoooked up to a powered site and to do those 2-3 minute reheats or 30 second melts.

but

planning on short use high drain gear is a pain for making cheap battery installations. put in a battery that can deal with the amps draw and you dont get a lot of reserve capacity so your lower load long duration ability suffers. (your fridge for example) if you stick in a deep cycle battery you hurt the battery every time you use the high drain gear.

If I had to guess.

To reliably be able to use a microwave (and there are 12v ones available but I'm discounting them for this) and get a decent service life out of everything I don't think you'd get away with less than 4 batteries (generic batteries, not top range optimas lithium or other exotics), 120w of high quality solar and a top notch inverter, not counting install, not counting hanging it off the vehicle battery(s) or having the engine running to support it. You wouldnt see much change from $2.5k as you've got 200w of solar maybe $2k.

[AndyG]

Had not heard of these before but all the reviews can't seem to praise them enough. I want one in the RR - don't worry about the van!

I'm sorely tempted, pop a few pies in, do your run, open the oven, open the fridge for a Coldie , all done.:)

[Homestar]

I have a top of the range inverter and 2 x 105Ah Full River batteries and while this setup is overkill for everything else I do, running even a small microwave properly is a bridge too far for it realistically.

The inverter runs the microwave fine, but a 3 to 4 minute run of the microwave drags the batteries down so much I don't bother any more,and pulled the microwave out as I can utilise the space and weight better.

I found that when I'm camping, I really didnt need it, it was just something else to lug around. The 40 year old gas oven in the van is a ripper and does everything we need now.

[Graeme]

Thanks everyone. My original suspicions appear to be confirmed. We had taken the house microwave on the few outings the current van has seen but didn't use it or the gas oven. I suspect that a gas oven would be necessary for extended touring but so would a larger van where kitchen space is not so limited.

We're soon to look at a used van that has a microwave but no oven. My wife has previously wanted an oven so I'm looking at options. The van is narrow, fibreglass composite, semi off-road with tandem independent coils and almost new with significant useful extras. I've also been offered a good deal on an already built new one but still no oven.

Thanks Terry - I'll look into your Ecopot suggestion.

[drivesafe]

Hi Graeme, if you are keen on having a microwave then there is a way to achieve it.

As has been pointed out above, they need very high currents available, to be able to use one.

If you were to use lead acid batteries, you would need at least 200Ah but 300 to 400Ah would be better to get a decent life span from the batteries.

Alternatively, you could go with a lithium battery, and I mean ?ONE? lithium battery.

To run a 1,600w ( 800w cooking power ) microwave for 15 minutes is going to need a tad under 40Ah of battery capacity. So a single 60Ah lithium battery is all you need.

For those doing the math, using lead acid batteries, you need to base your calculations around a 12.0v battery supply voltage.

With a lithium battery, the base voltage is 12.8v.

Graeme, if you think you need to cater for a 20 to 25 minute cook time, then a single 100Ah lithium will easily do the job.

You can use the reverse calculations to work out the drive and/or solar recharge times needed.

200w of solar will recharge the battery on a daily basis, while a drive time of around an hour to an hour and a half will do the same. NOTE, this is just to replace the energy you used while cooking with your microwave.

Anyway, this is just something to consider, if you are planning to keep the "new" van for some time, and plan to use it regularly.

[Graeme]

I had forgotten about the performance characteristics of Lithium batteries. I'm reminded when the battery in my drill goes flat which it did a few days ago as it works seemingly at full power then very quickly expires, but then recharges in only a short time.

I note that Lithium batteries are offered as alternatives in some of the quite expensive off-road vans which I thought was just to reduce weight but there are other benefits too.

[dan007]

In my van had a cheap inverter. Oven would run but not cook food. Had to go to a pure sine wave

Sent from my GT-I9507 using AULRO mobile app

[Graeme]

In my van had a cheap inverter. Oven would run but not cook food. Had to go to a pure sine waveThat comment might have saved some disappointment - thanks!

[Aaron IIA]

How about putting the inverter in the car. Run the engine when using the microwave, and the alternator will provide most of the power needed, reducing the load on the batteries.

Aaron

[Blknight.aus]

I'm sorely tempted, pop a few pies in, do your run, open the oven, open the fridge for a Coldie , all done.:)

you realise that if you're going to do that you have this humping great lump of heat generating metal under a door that will cook pies to perfection every time?

They have not yet released a landrover that does not have space in it engine bay to cook up one of the several formats of pies available or garlic breads.