Microwave off grid ?

[Benson]

Hi Folks.
I wanted to know if it is possible to run a microwave whilst off grid, if so which brand and wattage.
I have 2 wet acid 90 amp for the habitacion powered by solar I have a 2002 B584 hymer.

 

[Kannon Fodda]

You can with a big inverter, pure sine wave type, probably minimum 1000W (most inverters will do their sustained main load and a short higher boost). That may support the 800W sized microwave but beware 8most microwaves have a high start load before settling. If you use sau 80% power on the micro, most tend to bitten do 800W for 80% of the time.

You challenge is also battery. How many of what size are needed to sustain the 12V amperage to the inverter.

 

[Guigsy]

It is possible to run microwaves from battery, but it does pull a lot of power. You'll need a true sine wave invertor to keep the microwave happy. And microwaves have a large inrush current when they start, so it'll need to be well over the 800w rating of the microwave. Probably nearer 1200w for a second or so. That's ~70amps when the microwave is on and quite a bit more than that for the start-up draw. You'll need to check the specs of your batteries for the maximum discharge current, but that might be a tall ask. Also... expect thick wiring!

 

[tonka]

I am just looking into this now as we are planning to do the same.
At present we have 2 x 90amp Varta batteries with a Kreiger 1100w Inverter. We often use a small air fryer reated at 1000w and no issues.
As Guigsy says, microwaves draw more power at start up and the figure quoted on the front ie 700w is the cooking power and NOT the input requirement..

I have found someone selling modified microwaves but they are just cheap models and once modified then sold at a much inflated price over £100+

This model gets some recomendations, 600w cooking power and around 1000w input..
Broken Link Removed

"Is that the maximum power consumption of the RHM1401B is a very reasonable 1000W or 4.17 amps."..

 

[Lenny HB]

As others have said it will work if you only buy a small microwave and fit a 1500 watt inverter.
But with only 2 x 90 ah batteries it will hammer then and shorten there life, fit another couple of batteries and you will be OK.

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[Benson]

Sorry, forgot to mention that I have a 1500 watt edecoa pure sine wave inverter which is powered directly via short chunky copper wired connections. Whilst I am on the subject I bought an overload switch from ebay which when it arrived looked a bit cheaply made so I dismantled it and to my horror it consisted of a piece of cheap tin. I am no electrician but what is the point in putting expensive copper cables if the current has to pass through an inferior conductor, these are widely available and I am concerned that people are using them and they are blaming their inverters for not working properly!

 

[tonka]

Well i have bit the bullet and ordered one of the 600w ovens..
Due here in a few days and then we are off to the 3 F rally... So will give it a test there..

Lisa you may want to park me in a corner near a fire point..

 

[peterc10]

"Is that the maximum power consumption of the RHM1401B is a very reasonable 1000W or 4.17 amps."..

That current is only if you are running it on 230v AC. At 12v DC the current from the battery will be over 80 amps

 

[Guigsy]

Sorry, forgot to mention that I have a 1500 watt edecoa pure sine wave inverter which is powered directly via short chunky copper wired connections. Whilst I am on the subject I bought an overload switch from ebay which when it arrived looked a bit cheaply made so I dismantled it and to my horror it consisted of a piece of cheap tin. I am no electrician but what is the point in putting expensive copper cables if the current has to pass through an inferior conductor, these are widely available and I am concerned that people are using them and they are blaming their inverters for not working properly!

Yes. There's been a couple of close calls on this forum from people that have used these cheap breakers. They get pretty hot under load and aren't that reliable as to what current they drop out at.

 

[tonka]

That current is only if you are running it on 230v AC. At 12v DC the current from the battery will be over 80 amps

Fully understand that
As said we currently use a 1000w air fryer and a 800w toaster with no issues.
Very aware of the need for solar to replenish the batteries so we dont have chips on a rainy day.

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[Spriddler]

I bought an overload switch from ebay which when it arrived looked a bit cheaply made so I dismantled it and to my horror it consisted of a piece of cheap tin.

Probably made in China for the mass market of people who want cheap.
'twas ever thus.

 

[Kannon Fodda]

Well i have bit the bullet and ordered one of the 600w ovens..
Due here in a few days and then we are off to the 3 F rally... So will give it a test there..

Lisa you may want to park me in a corner near a fire point..

Might need to get the marshalls to enforce a Tonka exclusion zone

 

[Lisa]

Well i have bit the bullet and ordered one of the 600w ovens..
Due here in a few days and then we are off to the 3 F rally... So will give it a test there..

Lisa you may want to park me in a corner near a fire point..

We were going to park you in the corner before you got the microwave!

 

[xsparks]

With all this kit does this mean that you will not be visiting "Spoons" Steve?

 

[Reallyretired]

Microwaves are usually only on for a short time so you should be OK with what you've got.
Don't be tempted to use the Microwave at less than full power. They operate at lower powers just by switching on and off so the starting surge is repeated throughout the cooking cycle.

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[Lenny HB]

Microwaves are usually only on for a short time so you should be OK with what you've got.

The problem is the high current draw on LA batteries if you want them to last you should keep to the C5 rate. On 2 x 90 ah batteries that is 36 amps max. A 800 watt microwave is going to draw around 74 amps allowing for inverter efficiency and on startup 110 amps or more, a good way of the batteries.

 

[MisterB]

I see you have now ordered a microwave, but for others, there is a company in Kent (en route to tunnel/ferry), that can convert some microwaves to a lower wattage. We had ours done for a cost of £50 - took him less than an hour!

 

[Lenny HB]

I see you have now ordered a microwave, but for others, there is a company in Kent (en route to tunnel/ferry), that can convert some microwaves to a lower wattage. We had ours done for a cost of £50 - took him less than an hour!

Probably just changed the magnatron.

 

[Terry]

Well i have bit the bullet and ordered one of the 600w ovens..
Due here in a few days and then we are off to the 3 F rally... So will give it a test there..

Lisa you may want to park me in a corner near a fire point..

We have a normal 700w MW on a 3500/7000 PSW inverter along with 2x 125 victron gels,works fine. The 600 w MW will just take longer to cook things. Not sure if that's kinder to the batteries or not but in house we have a 800 w MW that takes 2 mins to boil a mug of milk while the 700 takes 2.20 mins on HU, On batts /n inverter 230/ 2.40

 

[Jev88]

Not sure if mentioned already but a company i know upgrades microwaves themselves for truckers initially. They add a soft start circuit and restrict power to 500watts.

Low Power Microwave Ovens - Truck and Caravan microwaves - Kitchenware

Low power Microwaves, suitable for use in trucks, caravans, welfare vehicles. Browse our range online now!&#9989 Fast delivery &#9989

www.kitchenwareonline.com

Truckers Microwave conversion.

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[tonka]

Probably just changed the magnatron.

Video on YouTube shows its the high voltage capacitor.

 

[jollyrodger]

Just my 2d worth
Last couple of vans both with m/w
1,samsung junior 600w Mw, 1000w modified s/w inverter 2x 110a batts.
200w solar. Pmw 20A regulator.
Worked well also ran toaster and kettle (not at same time)

2, Toshiba 800w variable plus grill Mw.
1500 pure sine inverter 30A mppt regulator.
Dedicated 2x 110 numax batts.
Worked very well but didnt like the grill part so ehu for that.
Terry and others will have a hive of Info at your meet

 

[MisterB]

Not sure if mentioned already but a company i know upgrades microwaves themselves for truckers initially. They add a soft start circuit and restrict power to 500watts.

Low Power Microwave Ovens - Truck and Caravan microwaves - Kitchenware

Low power Microwaves, suitable for use in trucks, caravans, welfare vehicles. Browse our range online now!&#9989 Fast delivery &#9989

www.kitchenwareonline.com

Truckers Microwave conversion.

thats who converted our microwave !!!

 

[Langtoftlad]

Against the grain but for me "offgrid" doesn't mean all the comforts of home.
Appreciate its a minority view but rather than spend all the time & effort and cash buying an underpowered Microwave, upgrading batteries, cables & solar etc, just take the opportunity of being 'away to try new cooking techniques

At home I have things like an airfryer, a Nespresso, a Ninja etc...
But away, I use a mokka pot & a ridgemonkey.

 

[tonka]

Against the grain but for me "offgrid" doesn't mean all the comforts of home.
Appreciate its a minority view but rather than spend all the time & effort and cash buying an underpowered Microwave, upgrading batteries, cables & solar etc, just take the opportunity of being 'away to try new cooking techniques

At home I have things like an airfryer, a Nespresso, a Ninja etc...
But away, I use a mokka pot & a ridgemonkey.

1 man
1 van
1 Frying pan...

Thats me for the past 20 years. But time for a change..
Anyway after 45 years of marriage it was the only think i could think of for an anniversary present.

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[Sheddy]

Just tested our setup, Daewoo 600w microwave,
3 x 80ah LA batteries,
1500 PSW inverter
Fully charged to start
Settled at about 90amps

 

[Guigsy]

Just tested our setup, Daewoo 600w microwave,
3 x 80ah LA batteries,
1500 PSW inverter
Fully charged to start
Settled at about 90amps


View attachment 646151

Wow, so over 1000w for a 600w microwave? They are supposed to be pretty efficient. I wonder where the excess heat is going? Is the invertor getting warm?

 

[funflair]

Wow, so over 1000w for a 600w microwave? They are supposed to be pretty efficient. I wonder where the excess heat is going? Is the invertor getting warm?

Ours on 900 watts takes about 1200 watts running.

 

[Benson]

Against the grain but for me "offgrid" doesn't mean all the comforts of home.
Appreciate its a minority view but rather than spend all the time & effort and cash buying an underpowered Microwave, upgrading batteries, cables & solar etc, just take the opportunity of being 'away to try new cooking techniques

At home I have things like an airfryer, a Nespresso, a Ninja etc...
But away, I use a mokka pot & a ridgemonkey.

Yes, I remember those days! Definitely less to go wrong reading some threads it is easy to get too much tech, although the missus likes her home comforts so it's more a case of compromise, Happy wife, Happy life!!

 

[ShiftZZ]

Interesting video