Microwave off ehu

[Wellington]

i know it’s not usual, and I know a lot people have no time for microwaves, but I find it incredibly useful. So I want to be able to operate mine off ehu, especially at overnight stops.

I favour an inverter, rather than a 12v microwave (because then I can use the coffee machine as well!) unless there is any reason to favour one over the other. Is there anything I should know (in words of one syllable please. I have only the dimmest awareness of what elecktrickery actually does!)

I am planning to drive to an aire or similar, park up, heat up a previously prepared meal for my child (takes one minute, max) and turn in. In the morning, I will run the coffee maker, heat milk for my coffee (again, two mins) and drive off again. I’m not expecting to wild camp for days. We have a solar panel and two leisure batteries, and there will be the usual occasional toilet/water pump and fridge use.

Is this at all feasible? I know most people are happy with gas, but with a small child, cooking meals at home and freezing them for later zapping is fast, convenient, nutritious and minimises washing up. Also, I have found no way of reheating a baked potato on a gas hob, and my daughter practically lives on them! When we’re in the van, I’m on holiday, and I want the most convenient option for me.

Do I need to worry about the batteries? I keep reading about not discharging them more than halfway, is there any sort of safeguard to prevent this happening? Is it worth upgrading to lithium batteries as well? Can anyone recommend a resource for learning about invertors for dummies?

 

[thebriars]

Nobody seems to have mentioned the slight problem of recharging the batteries after using a microwave, and this could be quite an issue and need large solar panels on the roof (more expense).

Also, handling the currents required for the inverter not only needs thick cables but proper heavy current crimped lugs which will need a hydraulic crimper to do the job.

 

[Duck Truck]

Get it installed properly
if you drive the van and have a split charger an hours run will bang the power back in

 

[tacr2man]

Go for the microwave , and a suitable psw inverter will also allow you to have a induction hob , boils water three times faster than gas good battery bank is a definate and with suitable solar pays for itself . JMHE

 

[hilldweller]

Of course we could think laterally. Sell the MH, go to a hotel and ring room service for the meal.

^{_{Subscribers  do not see these advertisements}}

 

[Khizzie]

"Yes you can do it your way but this way is ten times better". What's the problem with that ?

Didn't answer the question, just basically stated this is what I think you should do. Rather than offer advice to the question. That's what's wrong with that. Imo.

 

[funflair]

Nobody seems to have mentioned the slight problem of recharging the batteries after using a microwave, and this could be quite an issue and need large solar panels on the roof (more expense).

Also, handling the currents required for the inverter not only needs thick cables but proper heavy current crimped lugs which will need a hydraulic crimper to do the job.

The OP did mention driving each day and that they had a solar panel so that should really handle the fairly limited inverter use mentioned, you can buy leads with the ends crimped on or as I did just buy a hammer operated crimp tool which worked a treat.

Martin

 

[haganap]

I have a MW and wouldn't be without it.

I have mine in use via a 2kw Pure sine inverter- word of note, many quasi sine or non pure sine wave will not work a MW.
I have the Microwave powered by two dedicated 110 batteries. This also powers Lady products, ie hair dryer and straighteners.
These batteries are charged by a purely dedicated B2B charger.
I have an app on my phone that tells me everything I need to know about the batteries, charge state etc etc.

 

[Wellington]

@Wellington I hope you are not being put off by what I will politely call the "banter" on this Thread. I might suggest a lot of it stems from folk not having properly read your question which stated.....

I’d expect no less! In general, I find varied replies helpful, and I appreciate people taking the time to reply, even if what suits me isn’t for them. I can completely understand that people think it’s bonkers to think about spending a grand or so on the ability to reheat a flipping baked potato! The reality is I am spending sixty thousand pounds to live in a metal box on wheels, another thousand (or two) for the invertor set up won’t hurt!

It’s worth it for me for a variety of reasons. My child has a muscular disorder which means she gets eosphageal reflux. She is nauseous almost constantly, and as a result is picky over her food, and must eat small meals every couple of hours or so. This means I need to take food for her wherever we go, and feed her often. (I’m widowed, so where I go, she goes.) Even on holiday, I will still need to feed her five or six small meals a day. The easiest way to do this is to freeze her usual meals in small batches, and zap them in the microwave.

Half a baked potato, or a couple of tablespoons of macaroni cheese or bolegnese heats up just fine in one minute (milk for coffee takes two minutes, and a shot off espresso tops it off nicely) I use sugarcane bowls and beechwood cutlery. No washing up, I’m on holiday too! This sort of thing is the difference between me getting a few minutes to chill out between chores, or not getting them. That’s worth quite a bit, to me! If I can microwave off grid, I think we will avoid campsites and fees a lot more of the time, meaning we can have a lot more flexibility and potentially saving a fair bit on site fees and restaurants over the six weeks I plan to be away this summer.

I will absolutely be getting professional fitting. It does help to know a bit about what I’m asking, though, both to prevent me being taken for a ride and so that what I get actually does what I want. (The dealer says it can’t be done, incidentally. No way of arguing the point unless I have some information!)

 

[Wellington]

I understand the need for a microwave, especially with a child, but have you thought of freezing in boil in the bag reusable bags? Think you could easily reheat on the hob and leave the microwave for use on site?

Possibly, although I’ve never tried. Bet it wouldn’t work for a baked spud, though. Kids eats every them damn day (if I never eat another one again it will be too soon!) and they make a good snack for her. It’s really hard not to just feed her junk with her eating pattern, so I’m reluctant to give up something that works so well for us. I might give it a go, it never hurts to have an emergency back up. Did you have an specific bags in mind, I don’t think I’ve ever come across anything like that?

I was also idly thinking about what else we use on ehu, and the answer is not much. To charge the ebikes, and the hoover, and herself has one of those electric overblankets she likes to sleep with in spring or autumn, but otherwise I’m paying for U.K. campsites with electric, to run the microwave for a couple of minutes a day. We were away for 71 nights last year, with just over half of the them on campsites, at around 20 quid a night. That’s 800 quid (I know they are cheaper abroad, but we don’t go abroad much) which starts to make the invertor look like a more cost effective option! I bet we could have a lot more flexibility here and stay in nicer places on the continent if I didn’t need power most of the time.

^{_{Subscribers  do not see these advertisements}}

 

[Wellington]

No-one seems to have picked up on this. My morning ritual is to put a mug of cold milk into the microwave for 1:11. It comes out tepid. Then it drenches 3 Wheatabix for a hearty breakfast. Except on the odd day when it drenches Alpen for an equally hearty breakfast.

So is that 1 min viable ? Most ready meals take considerably longer. And all of a sudden the nice simple plan turns to brexit.

But easily solved, buy a generator.

[ NB that last sentence falls into the banter category even though it is a feasible solution ]

Adult meals take longer, for sure. I make her meals in batches and freeze them in portions a cupcake tin. If they are defrosted, they heat through in a minute, easily. It’s only a couple of tablespoons. The baked potatoes are not as hot as I would have them, but she’s little. 2/3 of a cup of milk for two mins with a shot of espresso is hot enough for coffee, I find.

 

[hilldweller]

I make her meals in batches and freeze them in portions a cupcake tin. If they are defrosted, they heat through in a minute, easily..

Now I get it.

So the deal is: install a 2000W PSW inverter and fit a change over switch so you can run the 240V sockets off inverter or hook up. It's been done many times on here, some use a manual switch, some use an automatic switch that switches once on hook up. With this you would use your microwave and coffee machine almost as usual.

Have you noticed @dave newell lvs on here, definitely one of the good guys to give you a quote.

 

[Wellington]

As a complete aside your remark about driving to an aire, eating a quick meal then turning sounds like a nightmare! We like to stop no later than around 14:00 then after a late lunch explore the surrounding area on foot.

We tend to have a leisurely start. Generally, we hang out in the van in the morning, driving off around lunchtime and go and visit something for the afternoon. Then we'll do a bit more driving to that nights' stop, arriving around 7, before eating supper and turning in. Usually two or three hours driving, split between the two sessions. Nothing much going on in the evenings, because one of us needs to be in bed before 9!

 

[tonyidle]

The OP did mention driving each day and that they had a solar panel so that should really handle the fairly limited inverter use mentioned, you can buy leads with the ends crimped on or as I did just buy a hammer operated crimp tool which worked a treat.

Martin

A half-decent hydraulic crimper can be had for around £25 on eBay.This is the one I use:

https://www.ebay.co.uk/itm/Heavy-Du...183950&hash=item2ac9fa6f9b:g:ybMAAOSwndBctieT

 

[autorouter]

I was also idly thinking about what else we use on ehu, and the answer is not much. To charge the ebikes,

When you get the inverter fitted, make sure you can use it while you are driving. Some MHs switch off all the habitation circuits when the engine is running.

You could charge the ebikes from the inverter while you are driving, to save taking from the batteries when you stop. Charging two ebikes from empty to full will take a large chunk of your battery power. About 25 amp-hours each, I would think. Two would take 50 amp-hours, which is half of your daily budget of about 100 amp-hours.

You might find that the standard charging arrangement for the leisure batteries struggles to refill them when you only drive for couple of hours or so. What happens is, the engine alternator is set up to charge the starter battery. Once the starter battery is full, it scales back the charging, even if the leisure battery is low.

To solve this problem, you can fit a 'battery-to-battery' (B2B) charger. It is connected between the starter battery and the leisure batteries. It increases the alternator output to a much higher level, and can fully charge the batteries in a much shorter time. It is a smart charger, and will not over-charge the batteries. They are easy to fit, with only three connections.

^{_{Subscribers  do not see these advertisements}}

 

[Reallyretired]

We have a microwave running from inverter Its fine if only using for a few minutes.

 

[Stonemags76]

Possibly, although I’ve never tried. Bet it wouldn’t work for a baked spud, though. Kids eats every them damn day (if I never eat another one again it will be too soon!) and they make a good snack for her. It’s really hard not to just feed her junk with her eating pattern, so I’m reluctant to give up something that works so well for us. I might give it a go, it never hurts to have an emergency back up. Did you have an specific bags in mind, I don’t think I’ve ever come across anything like that?

I was also idly thinking about what else we use on ehu, and the answer is not much. To charge the ebikes, and the hoover, and herself has one of those electric overblankets she likes to sleep with in spring or autumn, but otherwise I’m paying for U.K. campsites with electric, to run the microwave for a couple of minutes a day. We were away for 71 nights last year, with just over half of the them on campsites, at around 20 quid a night. That’s 800 quid (I know they are cheaper abroad, but we don’t go abroad much) which starts to make the invertor look like a more cost effective option! I bet we could have a lot more flexibility here and stay in nicer places on the continent if I didn’t need power most of the time.

Something like this?
Amazon product ASIN B07HJBXBSY

 

[138go]

Think your Dealer maybe right about it not being feasible. If you are thinking of removing the built in oven what are you going to replace it with. Not seen a combi oven that would fit in place of a Thetford cooker. You will have to fit the microwave in a cupboard or buy a different MH that has one already fitted.

 

[Wellington]

Think your Dealer maybe right about it not being feasible. If you are thinking of removing the built in oven what are you going to replace it with. Not seen a combi oven that would fit in place of a Thetford cooker. You will have to fit the microwave in a cupboard or buy a different MH that has one already fitted.

It doesn’t have an oven. Dealer is fitting a built in micro in place of one of the drawers, which they are happy to do, but adamant that an inverter will not be able to power it. Of course, we know they are wrong, but I’d rather they said no than did a poor job of it.

Surely, if you can fit a micro, you can fit a combi? They aren’t that different in size, are they? If not, I’m happy to just have a micro and take along the halogen oven for use on hook up, but as a combi will do both jobs well, and not need hauling out of the the garage for use, it seems sensible.

 

[Lenny HB]

One thing that has not be mentioned is the fact that if you want your batteries to last you shouldn't high current loads from them. Gel batteries you should try and keep the load to 20 amps per battery so with a microwave start up of 125 amps you would need 6 batteries to spread the load if you want long life. With ordinary flooded cells you will probably only need 3 or 4 as they can stand higher loads.
Having said that a lot of people do get away with caning their batteries but just be prepared for replacing them more often.

^{_{Subscribers  do not see these advertisements}}

 

[Minxy]

It doesn’t have an oven. Dealer is fitting a built in micro in place of one of the drawers, which they are happy to do, but adamant that an inverter will not be able to power it. Of course, we know they are wrong, but I’d rather they said no than did a poor job of it.

Surely, if you can fit a micro, you can fit a combi?

It might be because a combi will get much hotter used as an over rather than just as a microwave, when you next cook at home feel the outside of your oven and compare it to cooking something in a microwave and you'll realise what I mean. Also a combi is likely to hammer your batteries a lot more than a microwave will.

 

[two]

I have used microwaves with modified sine wave (MSW) inverters. It can work, but there are all forms of 'modification' and some will be much better than others. Pure sine wave (PSW) would be better. Everything worked off MSW except some hair curlers. PSW would provide greater assurance (at a cost).
I'd check your battery chemistry, though. Gels don't like high current, they perform best at low drain rates and so are not suitable for this. Lead-Acid (or AGM) is what I'd prefer. If you can afford a Lithium battery installation, there'd be no problem. Just remember not to get carried away with the notion that you have 'mains power' with you - it's a very limited supply.
Microwaves are heavy, so allow for that in your payload. I'd try to have it installed in a way that it could easily be removed. You may find a better alternative and you will want to sell, eventually.

 

[autorouter]

Microwaves are heavy, so allow for that in your payload.

Here's some more useless information. There are two kinds of microwave. The standard type uses a big heavy transformer - it needs to be so heavy to transform the mains power to the high voltage that the microwave element needs.

The second type uses what they call 'inverter technology'. The mains is changed to a high frequency wave before it goes into the transformer. That means the transformer can be a lot smaller and lighter. The difference is quite noticeable.

 

[Lenny HB]

The second type uses what they call 'inverter technology'. The mains is changed to a high frequency wave before it goes into the transformer. That means the transformer can be a lot smaller and lighter. The difference is quite noticeable.

Unfortunately usually only found on the larger more expensive ones.

 

[autorouter]

I'd check your battery chemistry, though. Gels don't like high current, they perform best at low drain rates and so are not suitable for this. Lead-Acid (or AGM) is what I'd prefer.

If you're not sure, post a photo of them, preferably with the label showing. Someone is sure to recognise them.

^{_{Subscribers  do not see these advertisements}}

 

[Wellington]

Fairly sure they are gel. I’ll upgrade to lithium, long term, though.

What’s the issue is with heat. I appreciate an oven gets hotter than a micro, but most uk vans have them in, don’t they? I won’t use the combi oven on battery, just reheating. Dimly as I perceive the function of currents and amp hours and wotnot, I’ve grasped that batteries are finite! I’m just thinking a few minutes reheating per day. And coffee. It won’t hurt to have the ability to charge the bike, but I like to hook up for a few days every week or so to let the kid see the same faces for a while. It’s also a good opportunity to do all the tanks and the laundry!

Good point about payload. We should be fine, but it’s always worth keeping an eye on.

I’ve stopped worrying about selling on. I’ve spent years trying to future proof life, and getting hit with the unexpected. I’m concentrating on trying to meet our needs now. I’ll worry about the future when I get there!

 

[Minxy]

What’s the issue is with heat. I appreciate an oven gets hotter than a micro, but most uk vans have them in, don’t they?

The difference being that if you fit an oven you need more air room around it (head room) to allow the heat to dissipate and often an external vent too, something which a microwave doesn't require so it is a more straight forward fit, this may be why they dealer is not willing to fit a combi as they won't want to accept the 'risk' associated with doing so in case the heat causes issues. Best bet would be to have a small microwave fitted and then get a Remoska, halogen oven etc for the times you want to use one on EHU.

 

[Minxy]

Here's some more useless information. There are two kinds of microwave. The standard type uses a big heavy transformer - it needs to be so heavy to transform the mains power to the high voltage that the microwave element needs.

The second type uses what they call 'inverter technology'. The mains is changed to a high frequency wave before it goes into the transformer. That means the transformer can be a lot smaller and lighter. The difference is quite noticeable.

How can you tell which is which though?

 

[tonyidle]

What’s the issue with heat.

All microwaves recommend a large (in motorhome fitting terms) gap around the sides and at the back. Such a gap isn't always achievable in a motorhome application and obviously oven manufacturers play it very safe. In my case, for example, I have a minimal gap but have arranged forced ventilation from outside the van. It isn't an issue as long as you're aware that parts of a microwave (especially a combi) can get very hot.

 

[Richard n Ann]

How can you tell which is which though?

Usually says inverter on them, my mums Panasonic said it on the front.

^{_{Subscribers  do not see these advertisements}}

 

[Wellington]

Usually says inverter on them, my mums Panasonic said it on the front.

Are they the ones that don’t need the turntable? I’m plan on having one, because the turntable makes a helluva rattle if you forget to take it out.

I will keep the halogen oven on board if it turns out the combi won’t work out (I haven’t asked the dealer yet). It’s going next to the fridge, so we’ll cent it through there. I’d prefer a built in, single appliance solution. I much prefer to keep things stowed where they are used, if at all possible, to make for slick pack ups.