Probably The Dumest Question Ever

Wombat · Veteran Member

Probably The Dumest Question Ever

twobob · Guru

Wombat. that quite an insightful sort of question. I would be interested in what you have in mind.

My first thought was, what do you currently have that is 240 (other than fridge), that you would replace.

My next thought was, how to do it. The van would be hard wired at production. Though you could use this wiring for 12/24, the outlets would need to be changed, for safety reasons. It would be near impossible to dual wire it. In all, I think it is only practically possible, depending on how many circuits and to where, that you could change over to 12/24. Then there would be the issue of the main power box, how to split it, safely, or install a second mains box for the 12/24.

Then there is the splitting off of the fridge circuit, which could only be done if it was hard wired separately.

My mind then drifted to changing the lights to LED. This should be easy, as the light circuit would be wired separately, and the LED save heaps of power, and no need to change anything else. Just install an 240-12/24 converter in the power box (look in bunnings at their downlights for this about $30)

In all, I cannot see at this stage, any advantage, other than the lights. Most 240v equipment is more efficent than 12/24v equipment, is readily available at reasonable cost, compared with the same in 12/24. All you will save is the cost of an inverter, and all you will lose is the efficency of it.

Just on that, it comes to mind about a UPS (uninteruptable Power Supply). From this forum, I have meant to check mine, for this type of use. They are high power and auto switching, with battery input as well as backup, and not too bad on the pocket. Larger than an normal inverter and heavier.

dave06 · Guru

nearly all vans have prewired 12 volt lighting installed, take your light cover off and you should see two globes, one 12 volt the other 240, take notice of the color of the wires feeding the 12 volt side, so the lights would not be problem just find the "entry point" of the corresponding colored 12 volt wires at the front of the van coming from the vehicles plug

the fridge should be able to be run off either gas (preferable) or the 12 volt system coming from the vehicle which will flatten your battery very quickly

I am not familiar with the make and model of your van and whether it has a forward boot or a position under seating that you could mount an "onboard" 100 amp minimum battery with asociated fuses and an inverter (usefull for a bit of other stuff) if so then mount a battery in there and run the 12 volt incoming wire from your vans loom in to that battery, this will be your power source

you then have to figure how to recharge this "onboard battery" I would choose solar, grab an 80 watt solar "breifcase" type one from a camping shop and run the wires through the built in controller to your battery this is the simplest of setups, easily understood and thereby easily repaired

this setup will give you an almost inehaustable power loop provided you stay within the power input limitations

install a simple inline volt meter just to keep an eye on things, do a bit of study, and you will find a whole new and interesting world will open up to you

good luck and you may contact me anytime if you have any further questions regarding this or any other matter

embkb · Member

One more consideration would be to use a House battery, as Dave says, but instead of picking up the existing 12v circuit, then:
Connect an Inverter - say 300 or 400 watt - to the House battery.

Install a 240v exterior OUTLET plug to the outside wall of the van and connect the 240v outlet of the Inverter to this.

Make up a cable to go from the exterior outlet plug to your normal 240v caravan inlet plug and use your normal 240v equipment (with commonsense).

Probably illegal though.
Michael.

xina · Guru

I have a High-Ace Campervan. There is 1 solar panel [large] on the pop-top roof. I have 1 house battery. I do not have an inverter. I have free-camped only so far, so have never used 240 volt electricity. My fridge-freezer runs on 240, and solar power.
I was told it would automatically change to 240 when I plugged in to that power source.
Haven't had any problems so far running it only on solar, but haven't been on any really long trips yet.
Cheers,
xina.

-- Edited by xina on Saturday 16th of May 2009 03:22:32 PM

Wombat · Veteran Member

My thanks to all for the advice. Much now to think about. My reasoning re 12/24 volts is that we want to be totally independant. If I get bogged down on the pros and cons.........i'll holler loudly. Thanks for the point re running the fridge on gas.......it was an aspect I had not considered. biggrin

Wombat 280 · Guru

I have a 100 amp/hour battery in the boot located in a plastic box with a 12volt outlet hard wired , I then made up a cig adaption and a female car plug using only the accessories and earth terminals in the female plug. I then plug the van male plug normally plugged into the vehicle into that , this then provides the completed power circuit to the internal 12 volt system. Naturally recharging would need to be solar or 240 mains supply at my next van park stop

The inverter idea suggested by embkb is one I must try, sounds like a goer. In the conversion from 12volt to 240 what sort of life would you expect from the battery before 240volt production was no longer possible

twobob · Guru

Bloody hell, I thought it was our Wombat (280) and he had something tricky up his sleeve. Turned out to be another Wombat, with a simple question.

Must wait for coffee number two, before reading morning mail, and watch out for the Wombats, their are multiplying.

-- Edited by twobob on Sunday 17th of May 2009 07:38:09 AM

dave06 · Guru

in my early years of travel I had the setup that michael explained and it worked very well, I cant see any problems with it, we only had one bit of trouble and that was the "drawdown" voltage to actually fire the inverter, they are power hungry little buggers, after a while we went tottally 12 volt and have not looked back since

when calculating your usage for power consumption, and if using the inverter as suggested, then be sure and take the power usage of the inverter into consideration along with all your other power requirements

we went to 12 volt for lighting, and the engel, batteries for the radio and gas for the second "in house" fridge. we have been camped for two weeks in one spot with only the 80 watt solar panel as the recharge system and it worked then and is still working now

whatever you decide and however you decide to build the system just keep it simple, you are the one thats got to fix it when it stops working

if you come up against something that is a bit tricky then give us a yell!!

try not to think about it too much, it really is dead simple, power for lighting or whatever and a way to recharge it, dont complicate it more than that

Wombat 280 · Guru

twobob wrote:

Bloody hell, I thought it was our Wombat (280) and he had something tricky up his sleeve. Turned out to be another Wombat, with a simple question.

Must wait for coffee number two, before reading morning mail, and watch out for the Wombats, their are multiplying.

-- Edited by twobob on Sunday 17th of May 2009 07:38:09 AM

Two Wombats in the same space can get messy I'm the hairy nosed one. Every time I wanted to use just Wombat as a sign in it was already taken so I attached my house number to it and it's like an America Express Card accepted everywhere

Wombat 280 · Guru

Went into the lab and worked out how long a 100amp/Hour battery using an inverter would last if powering anything other than a very light load = Fridge for get it, Microwave for get it, lights days, TV for get it, Radio days , Water pump days, Bar heater for get it . Conclusion unless you have a reliable back up charging source and and a bank of batteries the general opinion is stick to Gas for cooking and use the battery for low wattage 12 volt light or gas lamp if free camping between charging stations .

Forgot to mention exercise caution when buying an inverter there are modified sine wave and pure sine wave Modified Sine Wave units are cheaper but may not run all your gear and in some cases will void any warranty or stuff the gear altogher

-- Edited by Wombat 280 on Monday 18th of May 2009 06:27:26 PM

Wombat · Veteran Member

Thanks 280. Every little bit of information helps. Electrics is one "beasty" I know nothing about. When we finally decide on the final setup we will put the van into a reputable workshop to have the work done. Whilst I am happy camping rough, She Who Must Be Obey'd (SHMBO'd) desires comfort (Moderate) at all times.
Regards

The Gnome · Senior Member

Can identify with all your sentiments re SWMBO .Got to luv 'em but where would you be without 'em.Mine is as precious to self even more than self could imagine.Sorry getting a little morbid. Been a very traumatic couple of years. In a bit of a down period.Best go.

-- Edited by The Gnome on Monday 18th of May 2009 08:28:10 PM

twobob · Guru

Now that I am back on track, with this question, I would like to follow up our Wombats latest thread.

While I agree, keeping "her in Doors" HID happy, is a noble thing, the pratically is different, when it comes to power use.

I just did a calc, then remebered I have my latest house power bill, and thankfully enough, both appeared to agree.

So if you want all the luxuries of home, on the road, get out your power bill. It will tell you what you use per day or what you have used for a period (just divide) in KWH. KWH is the technically correct way of writing KW, they are the same.

Now for argument sake, a 100ah battery, used via an inverter, will provide about 1KWH for the day, without recharge.

So, I used 14.8 KWH per day, therefore I need 15 batteries!!!

This may help those that are not sure, and demostrate the need to use other forms of energy ie gas. It will also show, what our Wombat is saying here, is spot on

dave06 · Guru

if you want a heap of luxurys and dont want the complication that seems to arise from a lot of people out of nowhere then just grab a generator and take that with you, forget 12 volt

we use 12v lights, 12v/gas fridge's and a fire, place a heap of freinds in that mixture and we have a very happy camp with a very happy wife, if you want more than that then stay in a c/park

Wombat 280 · Guru

The inverter idea suggested by others got me thinking so I went and asked others of greater knowledge than myself in this field as I didn't think my test results rang entirely true regarding microwaves, this is what came back and after checking the writer is correct in the calculations .

Hi Wombat, while your calculation is correct, this current figure only covers about half the power required to operate a 900 watt microwave oven.

If you have a look either in the operating manual for the microwave or have a look at the compliance label on the back of the microwave oven, you will get the total 240 vac wattage required to operate the oven and this is usually about double the cooking power wattage.

As posted earlier in this thread, you would be better off getting a small gas cooker.

So to run a 900 watt microwave oven and allowing for about a 10% operating efficiency of an inverter to power the oven, you are probably looking at about 165 amps at 12 volts.

This sort of current can only be provided by a bank of 4 or more 100 A/H batteries, not off 1 or 2 batteries and even then, you would not want to be using the oven for more than a few minutes, just long enough to heat up a cup of water for coffee or tea.

Pulling high current levels like this for longer periods, even from a bank of four 100 A/H batteries, will seriously shorten the batteries operating life span.

Microwave ovens are one of a number of devices that should be left to being power from mains AC only.

Wombat · Veteran Member

Dear all,

Thanks for all the info and advice. No caravan parks (Except when needed) but a whisper quiet Honda generator for the 240 volt stuff in the country. Once again thank you one and all.

Regards
GOF and SWMBO'd

Wombat 280 · Guru

Way to go , Certainly cut's out all that worry will it work or won't it

Basil Faulty · Guru

Traeger made his name with the treadle radio, maybe somone could come up with the treadle TV and Microwave?????

Wal · Member

Or a gas powered mirowave?????