# most popular size of inverter



## 88847 (May 9, 2005)

What is the general opinion on invertors,

what is the optimum size to get, i dont want to get a 1500watt if i dont need it

what are the most common things you use the invertor for other than tv/dvd

Paul


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## DABurleigh (May 9, 2005)

Paul,

For charging various devices using their dedicated mains adapters, satellite receiver or DVD, or running a mains "desk" fan for air movement, usually a 150W one is enough and they tend to be silent, not having a fan. A sine-wave one may be necessary for electric tooth brush chargers, some mains fans, and some lighting.

For a conventional colour TV, 300W can be safer. I have a Maplin 300W modified-sine wave inverter with quiet(ish) fan.

Above that, use is more specialised. I have a 1300 watt one on order for various reasons, but that's not typical.

Dave


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## 88847 (May 9, 2005)

Dave 
Thanx for answer, i did think of getting one about 500w as i will only be watching dvd and using laptop, but no doubt as time goes by i will realise that there will be something else added to the list.
Life is not as simple as it should be

Paul


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## DABurleigh (May 9, 2005)

Paul,

As long as you appreciate that a 500W one will have a fan, that is not silent, and that its stand-by (no-load) current will be a lot higher than a 150W one.

Dave


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## 88847 (May 9, 2005)

Dave

Thanx, understand what you are saying, will spend time looking thru websites to find one.

Where did you get yours from? , if you dont mind me askin

Paul


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## DABurleigh (May 9, 2005)

Paul,

300W 12V modified sine wave inverter from Maplin £20
http://tinyurl.com/6cc3p

1300W (1600VA) from Victron
http://tinyurl.com/4h92q
http://stores.ebay.co.uk/VanGear_Victron-Energy_W0QQsclZallQQtZkm

Dave


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## Brambles (May 12, 2005)

Hi Redone, with all these things you are planning for your M/Home you will need to upgrade the suspension - LOL. Hope all is going well and you are learning how everything works. 
Jon.


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## 88724 (May 9, 2005)

Hi 

The stand by current of a good Invertor (even different sizes) Like Sterling's switch mode does not vary greatly at all

My 150w Sterling uses a tad under .7 amps and my 1800 w Sterling is the same.

If you are only ever going to use TV DVD ETC LOW WATTAGE STUFF, it makes sense not to pay for a bigger invertor.

More tommorow

Night for now

George

Be careful what you buy all invertors are not rated the same way.


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## DABurleigh (May 9, 2005)

George,

The current (ha ha) Sterling 150W offering is even better at 0.2A stand-by.

http://tinyurl.com/4rjv9

Dave


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## DABurleigh (May 9, 2005)

Yes, stand-by current is not the real issue. Rather I should have said that inverters are most efficienct at their rated output, so one other downside of "future-proofing" of buying a bigger one than you need, as well as the extra cost, is that the inverter is less efficient running "ticking over" as it were, causing unnecessary drain from your batteries.

Dave


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## 88724 (May 9, 2005)

Hi DA

Both my invertors are the latest spec, I have tested the 1800w many times now, but the 150w as only been tested once I did photograph this dual test but cannot find the 150w Photo.

Anyway onwards, I will try and run a test to see which is better, do be aware that Sterling seem to be the only company to accurately rate their products.

I really need to get a chart drawn up but basically it runs like this.

Continous rating

A Sterling 1800w invertor will run at 1800w 24 hours a day 7 days a week at Temperatures up to 40 Degree's C

Just as an example the Victron 3000w Combi (Multi) on the surface you would expect that it is a 3000w Invertor however on checking their specification carefully you will see that it is rated at 3000 w only at 25 degrees and only 2000w at 40 degrees, check the small print here

http://www.victronenergy.com/DatasheetsPDF/SinusInverterChargers/GBPhoenixMulti.pdf

So they claim 3000w but actually supply a 2000w invertor

They also claim 95% efficiency wonder what that claim is worth?

I have also never understood why when a company says our invertors continous rating is 1000w, but then say its at the P30 rating (this means that it will hold the 1000w for 30 MINUTES !!)

Is your idea of continous 30 mins or do you agree with Sterling that continous means indefinately

Couple of more pages of discussion re Invertor and proper rating etc

http://www.motorhomefacts.com/postx1324-0-30.html
http://www.motorhomefacts.com/postx2116-0-15.html

NB its not only Victron, I have not been able to find one other Invertor that is rated properly in Europe, In America they are using The ABYC rating (same as Sterling)

BTW on no load current if you are not using the invertor why not switch it off? Most peoples usage will be to say watch TV DVD so when finished switch off the Invertor, Then your no load (ie not being used rating) is Zero, Unless you have a continous use like me with fridge then the no load or quiescent current is a bit of mute point.


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## Maxonian (May 13, 2005)

Inverters are a well aired topic on this forum - it's worth searching the database for previous threads.

It's always seemed to me that the critical factor is the battery and not the inverter. Remember, each 100W of inverter output draws 10A from a 12V battery (rule of thumb, assuming losses). 

So, for example, a large inverter supplying a 1500W load will draw 150A from a 12V battery and most European MHs are fitted with only one (or at best two) 80AH or 110AH batteries. 

Large inverters need substantial battery capacity (and the ability to recharge them).

Raymond


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## nukeadmin (Oct 10, 2003)

well i have the 1200w Victron and i can confirm that even when the outside temp was 29 degrees C and even hotter inside the MH, my 1200w Victron was powering my 1400w hoover, so they must be overly cautious on the specs as otherwise this just wouldnt work 
granted the hoover was only on for 10-15 minutes but nonetheless thats better than i expected


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## 88724 (May 9, 2005)

Hi Nuke

Is that a straight Invertor ie not a charger invertor or multi?.

Whichever it is Victron rate there products poorly to me a continous rating is continous not 30 mins and not at unrealistic temperatures, the temperature is the units own heat + Ambient not the abient temp alone.

Fact is unless kept cool a victron falls over very rapidly at its "supposed" continous rating and if it didnt they would not say it in their less than clear spec sheets.


George


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## RobMD (May 9, 2005)

There is an inverter that only switches on when there is a power demand, so uses no power when not in use.
The leaflet I have (picked up in a show a while back) is for "Power Box", and their Tel. No. is 01462 682705.

They market a Square and a Sine wave device from 250 watt to 2000 watt.

Don't know if they are still around as I didn't see them at the York show, but having an a.c. supply to hand all the time (battery power permitting), seems a good idea.


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## nukeadmin (Oct 10, 2003)

it a multiplus 1200


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## 88724 (May 9, 2005)

Hi Rob

A standby device would need a (quiescent) survival current, no Invertor yet produced as achieved this low standby current yes but they all use some while on standby.

Usually (but not always) standby switched invertors are trying to mask a poor quiescent whilst running.
George


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## Anonymous (Nov 10, 2000)

Coming from long term live aboard sailing tends to make you a little more independant of mains electricity and workshops I carry 2 inverters a 150 watt and a 1500 watt, the 150 watt model was used for mobiles, computer, small soldering iron and other small appliances. The 1500 modle was used for power tools, vacume cleaner and microwave, this I only use with the engine running. With a medium size solar panel and a large wind generator and 200 amp domestic battery kept me completely independant from the mains.

Doug...


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## 88847 (May 9, 2005)

Hi guys

having read all these posts i am not as sure as i was when i thought i would JUST buy an invertor, there has been a lot said, but there does not appear to be a specific type , and i ASS u ME it is up to the individual
As i do still not have the knowledge i shall start off small and things can only get better
Thanx for the lesson

Paul


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## 88724 (May 9, 2005)

Hi Redone

If you are Sticking with TV DVD get a 300w Sterling you will not be disapointed. 300w gives a good margin for useful stuff without massive battery bank.

Buy a Victron it will not disapoint you either (unless you expect to use the continous rating ) it will cost you more and do less, but they are also very good quality gear. 

I had an email asking why I thought Victron were so bad, Please read what I sayu carefully I have not said that victron are poor quality or poor invertors.

Other than the Bad system of rating the output, they are fine machines from a very good company, there technical literature is great.

George


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## RobMD (May 9, 2005)

I know what you mean George - But the leaflet states categorically that NO current is drawn when not in use and it can be left permanently connected to the battery. I assume by this that it is auto-switching, and is actually off when not in use.


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