# Need advice on use of inverters



## Jacques le foot (Jan 16, 2010)

Hi Folks,
  I am wondering if it is feasable to use my 750w George Forman grill through an inverter. 
  I'm thinking it would be very useful to use it at lunch time, when we are going to be motoring again through the afternoon to recharge the leisure battery. It would save gas during our journey down to Portugal.
  Wouldn't want to risk 'cooking' the 12v wiring system though! 
 If it is possible, what size inverter would I need?
Your thoughts appreciated.

Jackie


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## Deleted member 919 (Jan 16, 2010)

Be very surprised if you could run it off an 850w inverter Jackie ,you would need to check out the wattage which should be on a plate on the grill,think you will find they are in the 1000-2000w range depending on size
Sorry Jackie read the post wrong thought you had a 750w inverter
Rob


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## ubuntu1 (Jan 16, 2010)

*inverter*

Yes its possible but you need a big inverter capable of giving you 1kw continuously. However its going to drain your leisure battery very quickly.


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## Deleted member 967 (Jan 16, 2010)

Jacques le foot said:


> Hi Folks,
> I am wondering if it is feasable to use my 750w George Forman grill through an inverter.
> I'm thinking it would be very useful to use it at lunch time, when we are going to be motoring again through the afternoon to recharge the leisure battery. It would save gas during our journey down to Portugal.
> Wouldn't want to risk 'cooking' the 12v wiring system though!
> ...



We run our George Forman on a 1600watt inverter.  The inverter will need a direct connection to the battery not a cigarette lighter type connection.  If in doubt leave the engine running to give a bit more power (Amps).

We can switch on the Self Energy EG-20 LPG 12volt generator which gives another 20 amps into the battery.  Self Energy EG-20 12V Automatic Generator | Conrad Anderson UK 
Joan will often start this up manually if we are using a high wattage appliance but I know it will run just on the battery alone if we are part way through a journey.


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## Norris (Jan 16, 2010)

Jacques le foot said:


> Hi Folks,
> I am wondering if it is feasable to use my 750w George Forman grill through an inverter. ...........................................................................................................
> If it is possible, what size inverter would I need?
> Your thoughts appreciated.
> ...


 Hi Jackie, most electrical stuff needs more current to start than it does to run, bit like a car needs a bit of throttle to set off but then will crawl along at tick over. If your George Foreman is a 750 Watt one, as you put in your question, it might need 1000 Watts (1KW) or even a bit more to start, but should then run on 750 Watts. I would think that a 1500 Watt (1.5KW) invertor would be ample to power this. You would need to wire it direct to your leisure battery with some pretty heavy duty wire to get the best use from it. I dare say someone with the correct technical knowledge will pop up and tell us what wire to use; I would just use the heaviest I could get!


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## garry01 (Jan 17, 2010)

*Inverter*

Hi i have an 8000w which goes to 16000w serge this will run any apliance but flatten battery so best to keep engine running or a gennie to keep battery up. I paid £250 for it on e-bay inc post from china. It was cheaper than a small one in any shop in the uk or ireland There are many to pick from on e-bay at cheap prices you will get a 3000w one for around £100 to £150 check it out 

Gaz


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## Kontiki (Jan 17, 2010)

Are you sure you mean 8000 watts  You must have to have really thick cables for something like that? Just seen them on eBay, but like you say if you are drawing anywhere near that power you need to keep the engine running, but I wonder if the alternator could keep up?


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## coolasluck (Jan 17, 2010)

John Thompson said:


> We run our George Forman on a 1600watt inverter.  The inverter will need a direct connection to the battery not a cigarette lighter type connection.  If in doubt leave the engine running to give a bit more power (Amps).
> 
> We can switch on the Self Energy EG-20 LPG 12volt generator which gives another 20 amps into the battery.  Self Energy EG-20 12V Automatic Generator | Conrad Anderson UK
> Joan will often start this up manually if we are using a high wattage appliance but I know it will run just on the battery alone if we are part way through a journey.






I thought your generator came on automatically John?


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## runnach (Jan 17, 2010)

It all seems a lot of effort.

I have never understood the idea of inverters ( missing at school that day)

It seems for less hassle Jackie is as well off getting the frying pan on a medium heat from the hob in a bit of olive oil 4 and a bit minutes aside.

channa


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## Firefox (Jan 17, 2010)

I use a 1000W inverter to run a 700W fan heater for a few mins sometimes. It could handle the George Foreman grill I'm sure. 10 mins at a time or so max to let the battery recover. 

But another thing I make use of is a heavy cast iron griddle pan on the gas hob. I use it without any oil. This can be used for any grilling activity and you can set it at a slight angle if you want, so the fat runs clear out of the meal in the grooves just like the George Foreman so I'd rather use that than the inverter.

By the way, inverters of that size come with with their own heavy cables which connect to the battery direct so no need to worry about your wiring.


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## Deleted member 967 (Jan 17, 2010)

coolasluck said:


> I thought your generator came on automatically John?



Yes the system is automatic if the battery gets down below 12volts it kicks in.

There is an override button to test that everything is OK.  Joan has got into the habit of pressing this when she put a heavy load appliance on.  It saves killing the battery.  The generator then starts and handles a lot of the battery load and cuts out at about 14 to 14.4 volts if left running.  The system will not cut in if the engine is running or when on mains hookup.  If the generator is running it will stop when the engine is started or mains hookup is put in.  If this happens it bleeps every 5 seconds or so until you switch it off.

I have two sets of sockets beside each other White mains or Cream inverter throughout the van.  If we are pushing the electrics on a site we can use both systems.

Channa.  I understood Jackie was trying not to use the gas to save it for later in her travels.  That is why she is thinking of using electric rather that the precious gas.


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## runnach (Jan 17, 2010)

John Thompson said:


> Channa.  I understood Jackie was trying not to use the gas to save it for later in her travels.  That is why she is thinking of using electric rather that the precious gas.



 ooops missed that bit 

TBH Jackie I have a Coleman petrol operated twin burner. The disadvantage is it should really only be used outside ( although I have used it on top of the mhome hob when I have been caught out with the gas) and never had a problem.

When camping, great for cooking outdoors especially when its hot.

I also have a petrol lamp that saves on battery drain lighting the exterior of the van when parked up 

And of course petrol is readily available and you always know how much you have got left.

Channa


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## garry01 (Jan 17, 2010)

Kontiki said:


> Are you sure you mean 8000 watts  You must have to have really thick cables for something like that? Just seen them on eBay, but like you say if you are drawing anywhere near that power you need to keep the engine running, but I wonder if the alternator could keep up?



I only have TV, laptop, and microwave 700w to run never overload just this was a good price for big watts so i bought it.
Gaz


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## garry01 (Jan 17, 2010)

Jacques le foot said:


> Hi Folks,
> I am wondering if it is feasable to use my 750w George Forman grill through an inverter.
> I'm thinking it would be very useful to use it at lunch time, when we are going to be motoring again through the afternoon to recharge the leisure battery. It would save gas during our journey down to Portugal.
> Wouldn't want to risk 'cooking' the 12v wiring system though!
> ...



Take a look at this inverter on e-bay item number 250550583886 £250.00 inc post 8000w once its wired right you will never have anyprobs its cheaper than buying one small one like 1000w or 3000w one in the uk


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## fugglestick (Jan 18, 2010)

garry01 said:


> Take a look at this inverter on e-bay item number 250550583886 £250.00 inc post 8000w once its wired right you will never have anyprobs its cheaper than buying one small one like 1000w or 3000w one in the uk


Why not just buy a 2KVA portable silent generator, like the Kipor unit. I bought a 2KVA a couple or years ago, and its so easy. It will even run the air con when necessary. Keep the inverters for smaller items. Just remember to chain it to the van when your not outside.......


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## Firefox (Jan 18, 2010)

garry01 said:


> Take a look at this inverter on e-bay item number 250550583886 £250.00 inc post 8000w once its wired right you will never have anyprobs its cheaper than buying one small one like 1000w or 3000w one in the uk



Completely wrong on two counts

(a) A 1000w inverter from Maplins costs about £80.00 so a 1/3 the price of that 8000W one.

(b) 8000W at 12V will draw 666 amps from your battery(s)! This is not suitable for motorhomes. You'd need a whole bank of 12v batteries to cope with that sensibly. Probably at least 8, not to mention the massive cables. Motorhomes can't cope with this kind of weight. That set up is more suitable for a boat. The biggest inverter you'd want in an average motorhome is 1000-1500w.


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## Tony Lee (Jan 18, 2010)

One critical bit of information is missing. What size battery do you have Jackie, and how many minutes would you need to run the grill at full power to cook your meal.
For instance, if you had a 100Ah battery in good condition and fully-charged, a half hour with the grill would be OK from the point of view of the storage capacity of the battery BUT would not be recommended because the actual current draw is way over the design limit for most batteries. May not matter if you are willing to accept the inevitable compromises involved in using any battery.

BTW Resistive heating appliances - kettles, toasters and the like without big motors in them, have no significant surge on start-up so you need very little extra capacity in the inverter to run them. TV sets on the other hand, can have large start-up currents that do cause problems with low-rated inverters


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## Tony Lee (Jan 19, 2010)

One major problem with fitting a hugely oversized inverter - as is the 8000Watt mentioned - is that you need to know the efficiency vs load figures to be sure you are not wasting a lot of power when running at the loads typically drawn in motorhomes.

That 8000W one has an efficiency (at full load) of 87% which means that 13% goes in producing heat within the inverter itself. That is around 1000Watts up in smoke - or to be more accurate, heat and noise.

Now usually the efficiency is best at full load and the figure drops as the load reduces. Manufacturers never give figures but supposing at a load of 1000Watts, the efficiency is only 50% (if anyone knows some real-life figures, let us have them) then you are wasting as much power as you are using. This would compare with say a 1500W inverter having an efficiency of say 85% at 1000W where you are only "wasting" a couple of hundred watts.

Big is not always better.

Damage to batteries caused by potentially huge current draws of big inverters is another factor to be considered.


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## Firefox (Jan 19, 2010)

It's interesting to see how many batteries are recommended for various sizes of inverters. The idea is you don't want too much current draw at any one time so you spread the load between the batteries

For a 1000w inverter, Elecsol recommend 4 x 110Ah batteries connected in parallel. This, I think, is a little over the top for low usage. I don't intend to run 700w off it for more than 10 minutes at a time. I think they err on the safe side because heavy discharge may damage batteries and they may get more warranty claims.

Even so I've got two 110Ah batteries connected in parallel, and I'm using it sparingly. But it shows for the this size of kit you should have more than one battery. To be honest at 25kg each, I can't afford any more than two batteries due to weight consideration.


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## n8rbos (Jan 19, 2010)

cook outdoors over timber collected from the woods etc, no petrol,diesel,extra batteries,inverters,jennies and a nice smell/warm off the fire.


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## Firefox (Jan 19, 2010)

^

That's what I'd do if it's not raining or freezing cold, there are woods available, and I could get away with an outdoor fire. UK is a bit limited for those opportunities, espec the first two


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## smifee (Jan 19, 2010)

Having MH'd for many years when I got this van it was definitely going to be my last van. So I was going to get it right this time.

I knew I didn't like campsites so wanted to be as self contained as possible.  Decided I didn't want to have to keep plugging in & unplugging appliances. Asked a company if I could have a system where I just press a button and all the vans 230v sockets have 230v. 

The system is 4 x 125Ah elecsol batteries, 2 x 75W solar panels through 2 regulators, 40amp mains charger, Sterling B2B charger and an inverter. 

The original inverter was a Mobitronic 3Kw peak, 2Kw for 30mins & 1.6Kw as long as there's enough juice in the batteries. I managed to fry the inverter with a faulty RCB  recently and it has been replaced with a similarly rated Sterling inverter. 

I don't have a battery monitor or solar panel readout. When I want to know if the batteries are charging I just use the Hymer control panel.

What do I run off it? Sat TV, breadmaker, toaster, Tefal Actifry, Gaggia Bean to Cup coffee maker, vacuum cleaner, car polisher, computer, battery charger ( AAs etc ), phone charger.

I could run the mini washing machine & domestic spin dryer as well but I use a Honda suitcase generator for them. I got the generator  for when I ran out of power but it hasn't happened yet in 5 years. Doing the laundry with the generator means it gets used which I think is good for it.

The batteries etc are in the van's garage and are not vented to the outside. In the 5 years I have had the van I have used 7.5 litres of battery top up water. I think this is because the charging systems are multi stage and use a higher initial charging voltage than standard chargers and this leads to gassing off. I check the battery levels every 6 months.

Did I get it right with this van? No I should have got a 3 axle van for the extra payload

How big a battery bank would I have then


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## smifee (Jan 19, 2010)

Father Christmas gave me The WoodGas Campstove XL but I haven't fired it up yet.

Will take it to Portugal next month and hope to get some use out of it.

Woodgas Stove Camping Equipment


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## tresrikay (Jan 19, 2010)

I think George should have stuck with his ukelelle and his wonderfull repetoire of songs............. " turned out nice again ...... HeHe "


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