What type of inverter?


I'm looking for feedback on inverters. There are a few difference types out there Eg pure sine wave, modified sine wave, new sine wave & just sine wave to name a few.

What I'm after is a 600w/1200w inverter to charge a laptop, phone, camera & run some small appliances like sound system drill & jig saw when the need arises. There also seems to be a large price range $60 to over $200 on eBay.

All feedback & advice good & bad will be appreciated.

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Reply By: olcoolone - Wednesday, Jun 13, 2012 at 21:14

Wednesday, Jun 13, 2012 at 21:14
There are only two types you can buy, pure sine wave and modified sine wave.

Pure sine wave are the way to go and good quality ones will provide a better cleaner outputs then main power in some cases.

Modified sine wave are cheaper and are not suitable for use on all electronics.

Pure sine wave inverters once were very expensive compared to modified sine wave inverters...... $400 for a modified and $1500 for a pure.

Now you can get a modified sine wave inverter for say $150 and a modified the same size for $600.

I would only recommend a a good quality pure sine wave..... try to find one that is sold around the world and is a recognised brand like Cotek.

Not all inverters are created the same.

If you want something good expect to pay about $0.80 per watt.

1000 watts is a good size for most applications.

As for the $60 to $200 eBay inverters.... good luck...... BUT if your going to use it for a $20 drill, sound system or computer then it should be fine.... I think!

Spend the money and have it for many years.
AnswerID: 488414

Follow Up By: Member - Michael & Jill - Friday, Jun 15, 2012 at 05:08

Friday, Jun 15, 2012 at 05:08
Thanks for the feed back.

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Follow Up By: P2D2 - Friday, Jun 15, 2012 at 08:38

Friday, Jun 15, 2012 at 08:38
Sadly there is so much poor, incorrect or far from ideal technical information posted here.
ROFLOL there is no such thing as "modified sine wave". If you could modify a sine wave you would be changing the laws of physics.

ROFLOL "There are only two types you can buy" oh dear!
There are three type of inverter, square wave, modified square wave and sine wave.

The most important thing when buying an inverter is to ensure the inverter is electrically isolated. That means there is no physical connection between the 12V input and 240V output.

Don't buy an inverter bigger than you need. A larger inverter takes more power to run itself and does not operate in the range of efficiency. An inverters optimum range of efficiency is generally around 70% of capacity.

Jaycar Powertech inverters are electrically isolated and reasonably efficient for the cheaper units. The Projecta Intelliwave are also electrically isolated and reasonably efficient. Recommend you stay well away from eBay as in the main the cheap units there are electrically unsafe. Morningstar Suresine if you want a supper effecient inverter with sleep mode and remote on/off.

MOST IMPORTANTLY NEVER EVER earth a portable inverter.
FollowupID: 763668

Follow Up By: olcoolone - Friday, Jun 15, 2012 at 09:26

Friday, Jun 15, 2012 at 09:26
Yes you are right but in this day and age of advertising nearly all retailers, resellers, wholesalers and manufactures refer to there modified square wave inverters as modified sine wave.

As you know a real square wave inverter will drive nothing more them a basic electric motor.

Some old people may have an ancient real square wave inverter floating around but as for new?????

Where can I buy a new square wave inverter from?..... I'm not talking about modified square wave (modified sine wave).

Why would anyone want a real square wave inverter?

The funny thing is the two companies you have listed , Jaycar and Projrcta list there cheaper inverters as modified sine wave...... now if modified sine wave inverters don't exist why are you mention these two companies?

The greater public recognisers the terms modified sine wave and pure sine wave as a house hold name when talking inverters.

So stop picking stupid little things out of my post that has nothing to do with the question.

And stop trying to discredit me with you unprofessional attitude!...... remember you told me you were a professional..... in what I don't know.

So back off and go and find something else to amuse you self with..... stop jumping on my posts and trying to knock me down, take it as a warning.

FollowupID: 763678

Follow Up By: P2D2 - Friday, Jun 15, 2012 at 09:46

Friday, Jun 15, 2012 at 09:46
ROFLOL ignorance is bliss. Duck and weave as you may, no good trying to hide your incorrect information.
"take it as a warning" oh dear I am quacking in my shoes ROFLOL
Don't pick little things, point out the MAJOR mistakes, biased vested interest and incorrect information constantly posted by some.
"nearly all' is not all.
No issue buying a square wave inverter or even a square wave inverter generator.
FollowupID: 763680

Follow Up By: The Bantam - Sunday, Jun 17, 2012 at 22:51

Sunday, Jun 17, 2012 at 22:51
OK lets cralify a few things.

Square wave invetrers ( machines that produce a whole square wave at the mains frequency)would be very hard to find......they are electronicaly very dirty, inefficient and crude items and would not be tolerated an almost any country under modern RF emmissions regulations.
Far more viable for DC to DC conversion applications than producing synthetic AC

A modified square wave inverter would be one where the corners of the square wave have been rounded of with filtration......again inefficient and less viable than more modern designs, the filtration its self introduces losses...if there was not filtration the losses would be in the motor or the transformer of the device being supplied.

A Modified sinewave...or more accurately an approximated sinewave is one where the wave form is approximated by stepped squarewaves......the more and finer steps the better the result......with modern electronics, just as cheap and far more efficient than the above two........with moddern RF emmissions expectations there has to be some filtration to clean up the wave shape.
The closer the approximation the less losses in the filtrationand in the devices connected.

There are several ways of producing "Pure Sine Wave" inverters......at their best they produce a wave shape more regular and consistent than a generator or mains power and can be very efficient doing it.

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Reply By: ABR - SIDEWINDER - Wednesday, Jun 13, 2012 at 22:46

Wednesday, Jun 13, 2012 at 22:46
Hi Michael

We have been selling inverters for many years and a good 600W pure sine wave will cost you $180 upwards, any cheaper you are loosing quality.

Make sure it has a USB charge port and has a full warranty.

You can try Jaycar, eBay or ABR any questions just email the supplier.


Derek from ABR

AnswerID: 488420

Follow Up By: Member - Michael & Jill - Friday, Jun 15, 2012 at 05:20

Friday, Jun 15, 2012 at 05:20
Hi Derek,

I've had a look at your 600w pure sine with the two outlets, USB port & indicator screen. Looks great & will go to the top of my list.

Thanks for the advice,
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Reply By: Racey - Thursday, Jun 14, 2012 at 10:08

Thursday, Jun 14, 2012 at 10:08
I agree with the previous comments. However, don't overlook the battery capacity needed to feed a big inverter. A 1200w inverter at full load will draw 100+ amps. Then be able to recharge those batteries.

AnswerID: 488431

Follow Up By: Member - Michael & Jill - Friday, Jun 15, 2012 at 10:11

Friday, Jun 15, 2012 at 10:11
Hi Racey,

Thanks for your feedback. Maybe you can give me more advice. I only intend to go to the 600w that peaks at 1200w. I don't expect to draw more then 300w for any extened period. I have a 360AH battery bank with 300W of solar panels feeding it. My question is say I was to use the inverter 2 hours a day drawing 200w what would the amp hours used from my battery bank?

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Follow Up By: Member - John and Val - Monday, Jun 18, 2012 at 07:59

Monday, Jun 18, 2012 at 07:59

How many Ah will you pull from your battery bank if you draw 200W for 2 hours? Allowing for inefficiency, you'll need about 250W from your batteries which is roughly 20 amps. 20A for 2 hours is 40 Ah.

BUT - will you really need 200W at 240 volts for 2 hours per day??? I can't imagine how you could use it. As said elsewhere, adapters are readily available to power most gear from 12 volts, which would be a more efficient way to go.

With 300W of solar and 360Ah of storage you have a good sized system quite capable of running your proposed inverter, but I wonder if you really need one.


J and V
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Reply By: The Bantam - Thursday, Jun 14, 2012 at 12:23

Thursday, Jun 14, 2012 at 12:23
Of course the question soo few ask is....

Do i realy need one?

you can buy 12 volt chrager/power supplies for your laptop and allmost every other battery powered device you could possibly own.

As for a sound system......Um why, there are so many 12V supplied audio products out there I can not see why you would need a 240v item

Most modern cameras and phones charge from a USB port and you don't need an inverter to get one of those...there are heaps of 12volt supplied devices that have a USB charging port on them.

As for running power tools of an inverter......forget it.

Remember you will be drawing in excess of 20 times the current demand from your battery than the item draws on 240V.

The there are all the hidden dangers of a portable 240V supply. Remember all portable 240V sources have to be considered unprotected sources......

AnswerID: 488443

Follow Up By: Member - Michael & Jill - Friday, Jun 15, 2012 at 11:14

Friday, Jun 15, 2012 at 11:14
Hi Bantam,

Yes I have asked myself the same question & my long term plan is to be totally 12V with all my electrical items but I still have a few to go & the cheaper option is to go with the inverter until I can have all 12V. Plus I will have the inverter for times I may need it in the future.

Thanks for your feedback,
FollowupID: 763685

Reply By: Dennis Ellery - Thursday, Jun 14, 2012 at 13:30

Thursday, Jun 14, 2012 at 13:30
I have a cheapie from Jaycar – a 300 watt modified sine wave.
I have it as a backup – it runs my electric drill, laptop computer, satellite decoder box and charges the mobile phone without a problem if needed.
Recently I lent it two mates to power their Vast decoder boxes and they have now purchased one each for about $70.
AnswerID: 488447

Reply By: Member - Anthony W Adelaide - Thursday, Jun 14, 2012 at 16:04

Thursday, Jun 14, 2012 at 16:04
We bought a Belkin inverter (rated at 300w constant output and 600w peak output) from a computer shop in Alice Springs for $170.00 a year or so ago and it has been more than adequate for our laptop and also charging cordless drill batteries, cameras, phones etc.
It seemed to be a good quality unit to me because it felt a little heavy and it is fan cooled. The unit is aprox 15cms x 8cms x 6cms in size with cig lighter plug on the cord and 240v plug in the face of the unit with a on/off switch and a battery level monitor.
It also has a 30amp blade fuse in the back of it. I don't know about pure sine wave or anything like that but it has been really good for us up until now and solved all our electrical requirements without any issues at all.

It can charge our laptop while using it and there is no need to have the engine running and the battery is fine afterwards.

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Reply By: Dennis Ellery - Thursday, Jun 14, 2012 at 18:29

Thursday, Jun 14, 2012 at 18:29
Even those that are quoted as pure sine wave are a bit of misnomer – they are all an electronically created sine waves and have to be considered modified. Some would be closer to a true sine than others but how good they are anybody’s guess - unless you tested them at various loads and analysed the output on an oscilloscope. If you ascertained it’s quality based on its purchase price you could be parting with good money for an unknown benefit.
AnswerID: 488458

Reply By: Motherhen - Thursday, Jun 14, 2012 at 22:11

Thursday, Jun 14, 2012 at 22:11
Hi Michael

Run your laptop direct from 12 v, and if possible use cordless tools and recharge the batteries on the inverter. A very small inverter will run battery chargers for phone and camera and although these can be charged from 12 v, using the inverter is much faster and a more practical approach.

We have almost everything in the caravan running direct from 12 v. Charging camera and phone batteries, power tool batteries if needed and using an electric shaver are the only things we run from the inverter.

Still which ever one you choose, buy a quality sine wave inverter.



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Reply By: P2D2 - Friday, Jun 15, 2012 at 08:47

Friday, Jun 15, 2012 at 08:47
To charge "charge a laptop, phone, camera" buy a 150W sine wave inverter"

"some small appliances like sound system drill & jig saw" to power a sound system takes a considerable amount of power for the time you power the unit. To power power tools a modified square wave inverter will do. Power tools have universal motors and will happily power from modified square wave.

To give you some idea, for every 10W on 240V you are looking at using 1A on 12VDC.

AnswerID: 488526

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