Running a 240-V Washing Machine on 12-VDC Batteries

Welcome to the world of learning and consequences. Quite different from world of dreaming and wouldn't it be nice. Welcome to our world.

milo

thanks for that milo!! dont suppose they do a front loader?? :O)America have all the good stuff...they also make a washer/gas dryer combi...would love one of them there critters (think gas pressure differs fro that in GB

You're welcome.

The idea was to show you that there is a different way of solving the problem than the way that you had identified. Just because 240 volts is the standard there doesn't mean that you have to re engineer your battery powered Direct current solution to that same parameter.

You are talking about mobile systems, ask instead how to replace the 240 volt systems in your washing appliance with similar performing equivalents using the battery power / alternator power available to you.

Clearly, there is a way...

milo

Thanks again milo...i am tinkering with the idea of replacing the 240 motor unit with a 12 volt unit...no doubt this will throw up problems..we shall see

You will save about 15% on energy conversion, worth having, but not enough to make the project worth while.....

There is a washing machine that you push backwards and forwards on a pathway. No electricity and far less water usage......

Milo wrote: You are talking about mobile systems, ask instead how to replace the 240 volt systems in your washing appliance with similar performing equivalents using the battery power / alternator power available to you.

REPLY: Milo remember the conservation of energy law. If you drop the voltage, the current has to increase by 20X in order to deliver the same power. You can replace the 240V motor with a 12V motor but it will be huge in comparison. Modern appliances are very compactly built and will not likey accomodate a much bigger motor frame. That leaves the heater elements in the dyer. An Italian firm tried to convert a 240V euro model to 120V American model. Its sold under the brand name Splendide. Most boaters and RV'ers who has one complain about the inordinately long time to dry even a small load of clothers. Going 12V would be just hopeless.

The practical and off-the-shelf solution is to get BIG inverters to create the needed 240V Ac at the required frequency. ( presumably 50Hz) The product manufacturer has already done the homework and development - including all the teste and fixing of mistakes in the early prototype. The washing machine is no problem. I will be the first to admit that powering a 4000 watt dryer is not practical unless you have either a huge battery bank or a honking big alternator on your main engine. And in fact this is what I base my designs on. The USCG 47 foot boats are in fact using exactly such a design of mine to power their air conditioning system using a 6000 watt inverter bank I built. But their 475 HP detroit engines ar also equipped with a 200 Amp 24V alternator. Its actually a 300 Amp unit but derated to 200A for military use. For civilian use I prefer to use a pair of 160 amp Leece Neville atruck alternators. These can be run in tandem with a Balmar regulator.

Not only does it deliver sufficient power but you can derate them with the regulaor and the more conservative output means longer life. And if you suffer a catastrophic failure in one unit; it means you lost 50% not 100% of your output. That gives you limp home power to get to someplace where you can get a replacement.

If you use an off-the-shelf inverter it is easy to also tap into the output power for using on other things. If you spent a lot of time customizing something just for the dryer/washer, its not as convenient for general use. Lastly, unless the washer /dryer was located immediately adjacent to th ebattery bank and the alternator you end up with huge copper cable runs from one place to th eother. Have you priced copper cable lately.

Far better to mount an inverter right next to battery then run small wires to 240V Ac applainces which may be a long ways away from batery location.

And finally a technical note. Cable resistance losses. I squared R means the losses in 240V cables are much less than in 12V cables for the same power delivery.

elnav

Thank you for the thoughtful and well explained comeback. I appreciate your taking the time to outline the first principles science behind the proposals.

You are correct in every respect except one.

That is the assumption to continue to use the 240 volt motor.

You have explained why not to use a 24 volt motor - and batteries.

Your original post which was rated by several as a good answer was a superb feat of engineering with the assumptions given.

It totally missed the ultility and practicality and expense of all the damn "balance of plant" to make that work.

As another poster pointed out, a more portable and less complex (occams razor compliant) solution is just buy a portable 240 volt gen set and then use it to run the existing washer.

Another poster pointed out the mass of the batteries needed for the 240 volt 'solution' must be around 500 kilos.

My point is that the original assumption that "240 v is king" is a constraint that paints other potential solutions into a corner.

He could buy a US 110 volt washer for a couple hundred bucks and a 5000 watt 110 volt generator for say $400 bucks and be much less mass and complexity than the 240 volt battery inverter approach. (Both less expensive if bought used)What would you estimate the cost and volume and mass of the 240 volt inverter battery etc. solution, vs the 110 (oh heck even the 240 v) generator and 5 gallons of fuel solution? as well as effect on mileage of Vehicle hauling all that ballast?

But the lower voltage 12 volt( or was it 24?) method is available off the shelf commercially as I pointed out with my RV link. It could be made to work, especially if one kept engine and alternator on while 'washing." (I thought.)

I'm just thinking like the horse of a different color, rather than accepting the local, parochial givens as "given."

Thats the way I think. Like I said earlier, Thank you for the thoughtful and well explained comeback. I appreciate your taking the time to outline the first principles science behind the proposals.

I'm a fan.

milo

Milo Every approach has drawbacks and that includes mine.

you and Andy suggest using a genset to eliminate the battery. But what about if your camping neighbor objects to running a genset? Some places even place restrictions on when you can run an genset.

When selecting a genset you must size it for "Peak" surge power or it will choke when trying to start an inductive load. Inverters on the other hand can absorb short term < 5 second surges. So the rule of thumb is you can size an inverter of 2/3 the capacity of the required genset for the same washer dryer load. Keep in mind that not all inverters are NOT created equal. And many of the RV inverters ae not suitable for driving inductive loads. I have run tests that demonstrate a 20% inprovement with pure sinewave inverter over the typical MSW type Rv inverter.

I had the test run by a product manufacturer on their air conditioning equipment and we supplied them with identicl wattage inverters. One was pure sine the other was our best MSW model.

As for your statement "It totally missed the ultility and practicality and expense of all the damn "balance of plant" to make that work".

Well I made a point of checking it out befoer posting. Turns out the OP already has most of that in place already.

BTW most portable gensets that are affordable are petrol fuelled. We were already told the OP has a very hefty truck chassis. That implies diesel. I foprgot to ask whay it actually was. Last thing you want is two different fuel systems on board.

Finding a cheap diesel generator is well nigh impossible. I know cuz I tried and ended up building my own diesel DC genset for recharging. A client of mine in Florida is also building his own per my instructions and for a boat being built in Turkey, we finally decided to have one custom built in the States. Reason being, we simply could not find a European builder willing to make one for a reasonable price. Yeah I know F-P does offer one in their catalog but rarely sell them. At twice the price of any other brand no wonder.

Most gensets be it diesel or petrol make noise. Fischer Panda is an exception, but who can afford the much higher price. I have used Honda in the past and found you can in fact buy an upgraded muffler at a reasonable price. .

Using your propulsion engine for generating power while you are moving this energy is then stored in a battery bank and is often the most reliable and quietest solution.

I had great hopes for the Stirling engine "WhisperGen" but they pulled it off the market. They are now doing new field trials with a second prototype but refused to sell it outside NZ. Told me to come back in another year about reselling that new model in north america.

I appreciate your comment about thinking outside the box. Unfortunately I have discovered that what's inside the box is occasionally still the better way.

Thanks. Your comments make sense. Different minds different solutions. Different decision criteria. Thanks again. (I have a honda 5000 watt generator and its less noisy than my neighbors stupid leaf blowers...)

milo

Good afternoon enlave, and hello again Milo, my CR 4 buddy!

The Robins Mfg Co. offers a single cylinder diesel powered generator for around $600.00 "If you shop around". It is fairly economical to run, and if I remember correctly, puts out about 6000 continuous duty watts, has a great warranty and service system. The price of the over and under apartment size washer and dryer combo, that both use 110/115 volts, 60 Hz electrical energy is around $500.00 if you get it discounted a places like Home Depot..

Somehow, even though I also like to get creative when it comes to building my own stuff, when it comes to reliability, and off the shelf replacement parts, and ease if installation of something that is needed as often as is a "home laundry system for a motor home", my advice would follow my dollars, and purchase and install a system that did not require me to get quite as creative as modifying 240 volt appliances, buying expensive alternators, and even more expensive batteries, and inverters that get fried when ever some critter manages to crawl inside looking for somewhere to get warm or smells like something great to eat lives there. I have to take a breath here.

You folks and others have gone to great lengths to offer advice regarding the "how to get it done' and have done an impressive job with offering the good advice. However my "Common sense approach to securing the best solution" Is to do something else to be creative, and just go out and buy the components that I suggested. Spend your leisure time fishing, and leave the laundry to the equipment that was carefully designed to handle the job in the smallest space allowable."

TooMuchFun

TooMuchfun; can you elaborate on the Robins Mfg. company URL to give exact product would be helpful. I did not find a complete generator package on their website. What I did find was a Ronbins Subaru engine of 11HP #27

Are you aware that as of Feb 1 last year tier I engines are no longer legal to sell in North America. Right now the only engines you can find are Tier III courtesy of your lovely EPA regulations. An additional little hiccup is most of these earlier Tier I and even some Tier II engines are not happy with ULSD fuel. the process required to produce ultra low sulphur diesel strips out a lot of the stuff needed for lubricity. You end up with a ruined injection pump in short order.

I just got a call this morning from one of my bird dogs who is locating small diesels for me. He tells me that a lot of the reefer trailers are being retro fitted with new power plants for this very reason. The injection pumps fail prematurely and are hellishly expensive to fix. The solution these guys use is to strip the power plant from damaged or corroded trailers getting scrapped. They stockpile the reefer plants and cannibalize them for parts as needed. This major change in fuels and engine have only come about this past year.

Back to the original query. The OP is located in the UK and thus only European certified equipment will be available. Everything I have read is that Europe is tougher on pollution controls than the US. This makes it harder to find small engines such as we are discussion. Honda EU series of gensets is among the limited number of products that do in fact meet European standards. Perhaps Andy can help out with more specific numbes and data. But from what I read of the regulations; it is also much tougher to modify and alter the original configuration of any motor if it has any effect on emissions.

BTW the Robins approach sounds exactly like what i did to built my own DC genset. A local supplier had a fire sale, ( to git rid of older model no longer compliant ) to clear out stock he could not sell after that New Years date. I got my diesel for $200.

Already had a number of the high output 3 stage regulated alternators in stock. It didn't take long to assemble the bits and pieces. But these utility engines are terrible for noise. Not recommended for use in normal RV's at quiet nature campsites. Definitely need a much improved mufler system. I'm still looking for a 17 HP engine to drive one of the monster 300 Amp 24Volt units. It delivers 8000 watts of DC power. The new Tier III models now on sale are quite a lot more expensive.

Driving a big alternator from the main propulsion engine while you drive to the next place is actually as cost efficient as any other approach. If you look at the specific fuel consumption curves of these engines you can see the net increase in fuel comsumption is not great. Taking an additional 5 HP from a 200 - 300 HP or so engine is a small change.

Good evening enlave,

I first learned about the Robin engine back in the mid 1990's. I had bought a generator that was occasionally used by the local power company on one of it's service trucks. I knew the driver of the truck, it was assigned to him from the first day the power company took delivery of it. He had informed me that the power company was upgrading a lot of equipment and he could get the gen-set for me for $250. This was a very good deal.

After I bought it I put it into storage for about a year before deciding to use it for powering up our hunting camp. After starting it up for a test run I found that it was only putting out 110 volts as one circuit was malfunctioning. I went looking for the Mfg., only to find out that they were no longer in business. I did however find out the name of the company that produced the alternator portion of the gen-set. I called and discussed the issue with a technician who informed me that this was not unusual for that alternator. He explained that there was likely nothing wrong with the machine except that one of the diodes had lost its direction. He explained to me just how to arc a current across the diode and suggested that I write down these instructions as I would likely need to do this again as this gen-set didn't much care for being left out in wet weather. Florida gets it's share of rain.

However before I found the Mfg. Rep., I took it to a local repair shop. The good folks there informed me that they didn't work on gasoline engines any more or anything attached to one. However they did show me a brochure of a Robin engine attached to a trash pump and one attached to an alternator. At the time I thought that a $600.00 price tag was a little steep.

A couple of years later, I was looking to price out a 2" trash pump with a diesel engine. That is when I learned that the MFG. of the Robin Engine was now being advertised as Robin/Subaru Mfg. I really don't know weather Subaru already owned the Robin Trademark or maybe purchased the engine/tooling and mfg from an original owner.

However I ultimately bought a Tecumseh powered trash pump that was set up with a propane carburetor. Maybe our thread originator should consider getting a gen-set that uses propane or compressed NG. These fuels are available all over Europe, and don't go bad if not used over long periods in storage.

As for adding the powerful alternators to the truck/motor home engine, it is my assumption that most of these kinds of vehicles spend at least 90% of the time parked. Powering up such an engine just to charge batteries doesn't sound very economical to me. As for the apt. sized stacked washer and dryer, Europe is famous for their smallish sized homes and apt. Therefore I would suggest that likely these same appliances are available locally. I suggest the thread poster take a look around.

As for the engines that you described, every one of these kinds of engines can be readily converted to run on propane and NG. They can also be ordered directly from the MFG. vapor fuel ready.

They may not be quite as fuel efficient, but there will be savings involved like fuel filters and additives, and cleanliness that will soften the added expense for the vapor fuel, if it indeed does cost more over there.

TooMuchFun

"Welcome to the world of learning and consequences."

Mostly consequences:

Doctors bury their mistakes.

Coaches' mistakes still get scholarships.

Lawyers' hang their mistakes.

Engineers' mistakes are out in the open for all to see.

I'm glad to see your still as feisty as ever europium I was thinking the answer was typically pompous as well . I'm glad you take the time to temper what would otherwise be a boorish discussion.

Hi.. Batteries are just a tank of electrical energy storage in the form of chemical process. Unless the energy stored in the batteries during non-wash hours is more than the energy required by your washing machine for full-wash, the conceptualised sulution will not work. You need to work on following :

1. Have one 12 V / 24 V/ 48 V DC to 240 V Ac Inverter.

2. Have a suitable 12 V / 24 V / 48 V DC battery bank which can store sufficient energy suitable for two washes minimum

3. Have a Solar Panel installed for Battery Charging

4. Have a Parallel Charging mechnism through the Alternator of the motor-home also.

I feel your electrical wizard will be able to help you on this.

rgds

Sanjeev

I will get there in the end...thank you for your help..god bless

Dear Elnav,

A staggeringly good answer!!!! I am a mech eng, but was curious to find the solution to Puskapusia's dilema. Your response was clear and concise. I wish him every success in his project

Stewie

hi stewie...I agree what an answer...so refreshing to read clear and informative advice...there can be many misleading voices in the wind regarding electrical matters..if you would like to follow my progress send me your email and ill send photos

thanks for wishing me all the best

Hi Puskapusia,

Best of luck with the project. It seems to have generated a tremendous amount of interest among the engineering community. Thanks for the offer of progress pictures. I would love to receive them! stuarthutchings@hotmail.com

Best Regards

Stewie

wow what a fantastic and helpfull reply!!!!! Just for the record i live in england, I am building my own motor home not because money is tight but i have allways dreamed of building my own home...like you i have lived on boats planes and trains if you know what i mean and have spent many many hours laying awake at night thinking just how im going to build my home...i would like to send pics to your email when it is finished, so send me your email if you are at all interested with my progress....i currently run a sterline marine smart charging regulator on a high amp output alternator i have so much power i just dont know what to do with it :O)

Thanks again for your clear, informative and very interesting reply..god bless

The size of batteries needed will probably weigh 500 kg or so and how will you recharge them? The losses in charging will be around 30% plus the losses in your inverter of at least 15%......that means 45% of the energy used will be lost. So you will need to almost double the amount of energy each time!!!!

Why not leave the washing till you are on a camping site and have a mains connection? or buy a petrol drive mains generator, they are very cheap nowadays. Just make sure that it can handle the full electrical load of the washing machine!

Also, you need quite large amounts of clean water, surely you are not going to use your water tanks for that, they will soon be empty. Water weighs 1 Kg per Liter, you will not want to pay the transport costs for even a quarter of ton of water surely?....and where will you pump the dirty water, many countries have strict laws on what happens with that waste water......

Most camping sites (most countries have laws not allowing camping outside of official camping sites, have you checked up on that?) have washing machines available as do many towns and cities....its surely cheaper to carry plenty of (far lighter!) clean clothes!

Hi Thanks for your reply...in response to your queries....5 litre per wash, one wash per week maybe 2...holding tanks for water...bio degradable washing agent...it is a luxury but one i think i deserve after travelling around the world in dirty clothes :O)

oh and very powerful truck to drag it all around..ermm 40 miles to the gallon..so not bad really

I even have a flushing toilet...i know iknow such self indulgent decadence..the shame of it!! :O)

I have a high output alternator, sterling marine regulator...24v inverter...Oooodles of power...dont know what to do with it!!!

I have a high output alternator, sterling marine regulator...24v inverter...Oooodles of power...dont know what to do with it!!!

REPLY

What ampacity alternator and what model inverter? Sounds like you are half way ther already. Why bother calling an electrical boffin. Sounds like you already have most of it in place.

But it ain't 'green' and there's nowhere to bury the co2.....

Why not just build yourself a trailer with a combination of gasifier, ICE (sized accordingly, storage for your wood chips, washing machine powered by the ICE, and water heating for said laundry purposes, and excess heating from the ICE exhaust to dry said laundry.

This way you could avoid the expensive heavy batteries, the ridicules cost to keep them charged and replace them as needed, or as the Chinaman said "no ticky no laundry. As an added benefit you can park your trailer containing your smelly laundry down wind from you, and offend your aggravating neighbors.

I think Daffy might like this one!

TMF

He he...Daffy do!

I'd add a small nuclear reactor tho............

I am not sure, what is green. Due to batteries, Solar or inverters are not green. Due to emmissions, generators are not green.

Even the washing machine itself is not green as it consumes electricity, which is not really green. Besides, drying spin is just waste of big energy, as this can be best done in open Sun.

Only green way is to wash the cloths in Pond, (with no use of detergent), even if ducks are around

The way I understand it is that 'green' is an expression for an environmental philosophy that has little real basis in reality. From a sentimental standpoint I'd like to agree with the proponents of this type of thinking but I have yet to discover any who actually know what they're talking about.

So, I remain a conservationist where it counts the most....by stepping lightly and do as best as I can to not damage and protect the environment around me.

Green is a political toy played by those who need a reality (their own) and a platform.

Green is also a marketing tool....and that disgusts me.

Green is also a not so nice color when one indicates that another is green with envy. If you really think that doing ones laundry isn't very green, then try standing in a crowded city bus next to someone who works out in the sun all day in the summertime and wears no deodorant, and is wearing the same soiled clothing that he /she has been wearing for several previous days.

Trust me on this one, you will feel the green!

TMF

While I agree that "Green" has been exploited as a marketing tool, the original intent or meansing was to suggest something has a reduced effect on the environment.

For example in BC we recycle a lot. Most households now have to sort their garbage into metal, glass and plastic food containers. We also seperate compostable food waste (no meat) from the non reusabel garbage. The land fill sites have seperate bins for each type of garbage. If you live inside an urban area many of the garbage trucks also have separation bins. This is a kind of green in that it reduces the amount of stuf that goes into land fill and what can get recycled.

Glass is crushed, metal memted down and plastic is often reground to pellets and then used for things liek drain and irrigation pipe where minor contamination ois not an issue.

Most of the northern region land fill sites also have a "Swap" shed or recycle depot.

Here you can drop of unwanted household items that still work but are not wanted. someone else may need or want this.

Since most land fill sites charge a tipping fee for any garbage but do not charge for stuff going for recycling there is also a savings inducement to the person dropping off garbage.

Whiel it doesn't reduce the carbon foot print it does reduce th eamount of stuff going into land fill sites. so in that sense this is a "green" project.

I make referance to Elizbeth May and her imbecile followers, who, in spite of themselves, are on my doorstep every week during the elections. Not once were any of them aware of what they were proposing........neither about silviculture nor habitat loss nor climate change. It was all about themselves and the latest buzzwords and not a tic of knowhow of observed fact. And yet they spoke in terms of possessing great knowledge without ever having had the experience of observation.

I don't trust them to make an informed decision.

well you can't trust a politician to give you the right time of day, let alone an intelligent opinion of current issues facing society.

Intelligent politician is an oxymopron. They may have street smarts; ....but intenligence? ...no way!

I tend to think of green in lower case letters. Like you I try to conserve, minimize my foot print somewhat. But I will not vote for a party just because they claim to be "Green"

Although I understand Andy's sentiments I am not sure how pervasive those conditions are. All the camp grounds I have seen have water supply and sewer hook ups. Most of the upscale Rv that I have worked on did have laundry machines on board. What's the problem? but not all camp grounds have hot water showers or laundry facilities. And those that do often have poorly maintained equipment that damage my clothing. Small apartment laundry machines, especially those from Japan ar ideal for RV or boat use if you have an inverter.

Great Opinion... I do agree..

rgds

Sanjeev

G'day Everyone,

Interesting posts all round and very informative.

I've been thinking about setting up a system similar to this and would like some advice. My idea is to run a LG 7.5 kg front loader off batteries charged by a solar panel. We use the machine about once, maybe twice, a week so batteries can take all week to charge.

Any ideas as far as solar panels, inverters and batteries go. Could you let me know the size or amount I'd need for each item?

Cheers - Joel