'quasi' Sine Wave Inverter ......

[Karizma]

I  have a Sterling Power Modified Sine Wave inverter on board Karizma and understand that they are little restricted on what you can use them for when needing 240v.

Whilst getting to know the boat over the last few months, we've realised we don't really need it, other than for operating the microwave on occasions!

Question is: i'd really like to use it to keep the MacBook Pro charged up whilst 'off grid' but have been concerned if it  would damage the charger (or the laptop) if I plug it in to a MSW inverter.

Anybody been 'brave' enough to try one? and was it ok?

[OldBerkshireBoy]

32 minutes ago, Karizma said:

I  have a Sterling Power Modified Sine Wave inverter on board Karizma and understand that they are little restricted on what you can use them for when needing 240v.

Whilst getting to know the boat over the last few months, we've realised we don't really need it, other than for operating the microwave on occasions!

Question is: i'd really like to use it to keep the MacBook Pro charged up whilst 'off grid' but have been concerned if it  would damage the charger (or the laptop) if I plug it in to a MSW inverter.

Anybody been 'brave' enough to try one? and was it ok?

Could try asking Sterling or an agent of theirs if nobody here answers.

[Karizma]

16 minutes ago, OldBerkshireBoy said:

Could try asking Sterling or an agent of theirs if nobody here answers.

 I have an email into them also

will share the feedback if I get a reply ..........

[OldBerkshireBoy]

Email works for me   Let us how you get on.

[MotorBoater]

https://www.powerinverters.com/pages/do-i-need-a-modified-sine-wave-inverter-or-a-pure-sine-wave-inverter

 

I don't think I would risk a laptop, is it under warranty ? If so I would check with laptop maker.

[Mouldy]

We used to have a modified sine wave inverter on Moonlight Shadow, however during one week on board we destroyed about three phone chargers and a tv.  At the time, we were unaware of the potential damage that could be caused by that type of inverter and it was only after other owners had other electronic devices destroyed on board that the issue was realised and the inverter changed for a pure sine wave type.

Obviously, when we bought Norfolk Lady, the type of inverter was checked before we used it to charge anything that could be potentially damaged.  Based on our experience, I would invest in a pure sine wave inverter before risking using your 240v supply to charge something like a Mac Book.

[Smoggy]

I was under the impression microwaves didn't get on with anything less than pure sine wave too so surprised to hear you say about it working ok.

[StillCruising]

I have a modified sine wave inverter. I have an older Sanyo microwave cooker that that has a clockwork timer that works ok albeit noisily. I wouldn't plug anything elctronic into it though. 

[annv]

Hi Modified sine wave is ok for normal power supply ie drill's, lights, older tv's hair dryers and mechanical timed microwaves BUT anything which is digital or has a thyristor controlled ie flat screen tv's and electrical items that have microprocessor controls ie push button controls need pure sine wave inverters ie mains type ac power. John

[grendel]

then you also have the shy self centred variety, often known as the introverters :-)

[TheQ]

33 minutes ago, grendel said:

then you also have the shy self centred variety, often known as the introverters :-)

Some other forums have the advantage of a GROAN emoji..

[Karizma]

11 hours ago, Smoggy said:

I was under the impression microwaves didn't get on with anything less than pure sine wave too so surprised to hear you say about it working ok.

Hi Smoggy, yes the microwave (that was also installed on the boat when we got her) works fine. Though it does look a few years old, so maybe a more modern model might not.

[Karizma]

9 hours ago, StillCruising said:

I have a modified sine wave inverter. I have an older Sanyo microwave cooker that that has a clockwork timer that works ok albeit noisily. I wouldn't plug anything elctronic into it though. 

"clockwork timer" ................ that sounds similar to ours 

[Karizma]

20 hours ago, OldBerkshireBoy said:

Could try asking Sterling or an agent of theirs if nobody here answers.

this is what Sterling Power said ...................

"Most laptop chargers I know are absolutely fine to run off of quasi. I know some Iphone chargers do not run brilliantly off of Quasi, but I have never heard of anything regarding a MacBook Pro. You may have to consult with Apple, I’m afraid. I believe personally it will be fine, but I have no evidence regarding"

 

still not reassuring enough to 'give it a go' 

[Islander]

Why not get a car charger for your MacBook. They look cheap enough compared to new Mac.

Colin. 

[CambridgeCabby]

Have spoken to a friend of mine who works for Microsoft Research and Development in Cambridge , he in turn asked one of their hardware guys , his reply was that you should never use a modified sine wave inverter on anything other than such things as electric motors eg. Drills , sanders etc , if using an inverter to charge any laptop or sensitive electronic device (including smartphones) then you must use a pure sine wave inverter and in his opinion for such items a slow charge through a 12v usb socket is often the safest method due to possible power surges with cheaper inverters 

[BroadAmbition]

That’s clear and reassuring to know. We opted for a Sterling pure signwave not so much for iPads and the like but for girly crew GHD’s 

Griff

[TeamElla]

Many will appreciate that domestic AC mains electricity delivered to your house is pure sine wave.

With all DC to AC inverters, it would be easy to produce a square wave output from the DC input supply. The difficulty comes in shaping that output to either approximate a sine wave output (quazi sine wave inverters) or with much more signal processing / output filtering, to achieve a clean sine wave output (true pure sine wave inverters).

Square waves produce nasty harmonics that are a death sentence to the switch mode power supplies found in most consumer electronics these days and quazi sine wave inverters still have some square wave content in their output. 

The more power you are drawing, the worse it gets.

So the big difference in price between the two types is no surprise and even the cheaper quazi sine wave inverters vary in the quality of their output. I wouldn't touch them with a bargepole.

Higher power inverters naturally use more expensive components that are physically larger, need big heatsinks and different board layouts, track thickness, track spacing etc to handle their rated maximum output loads. These all include at least one cooling fan and must be fitted in a cool area with sufficient space around them to allow proper circulation of air for cooling.

[Oddfellow]

Doesn't a Mac Book Pro charge off USB C? 

[TeamElla]

They do Andy, but I don't know how the supplied 61w USB C Power Adapter (that plugs into AC mains) would fare on a quazi sine wave inverter's output. I wouldn't take the risk, but anyone doing so should unplug it quickly if it starts to get hot.

Rgds,

Steve

[TeamElla]

"Higher power inverters naturally use more expensive components that are physically larger, need big heatsinks and different board layouts, track thickness, track spacing etc to handle their rated maximum output loads. These all include at least one cooling fan and must be fitted in a cool area with sufficient space around them to allow proper circulation of air for cooling"

Let's not even get into how much they draw from your batteries. Don't even think about using one for heating. We find our modest 350 watt unit to be a good compromise.

[Oddfellow]

1 hour ago, TeamElla said:

"Higher power inverters naturally use more expensive components that are physically larger, need big heatsinks and different board layouts, track thickness, track spacing etc to handle their rated maximum output loads. These all include at least one cooling fan and must be fitted in a cool area with sufficient space around them to allow proper circulation of air for cooling"

Let's not even get into how much they draw from your batteries. Don't even think about using one for heating. We find our modest 350 watt unit to be a good compromise.

An inverter that's just on and dormant will draw very little from the batteries (unless it's a terrible design) and the load on the DC supply goes up as demand on the 240v end of the system increases. A 61 watt supply is sod all in real terms. 

I charged my Legion laptop twice during a motorhome trip a week or two back off a 350w pure sinewave inverter and the battery was barely impacted. My only charging was from a 150w Solar Panel. We have about 10 USB sockets installed in the van and these are mostly used at night to charge all the camera equipment and phones. We had zero energy concerns using just one 110AH battery and a 150w solar panel. 

Indeed, if you use one to run a heater, you're gonna cane the battery bank in no time, but for a laptop charger (and at 61watts, you're gonna need it for only an hour or so), with a decent battery charging system, you should not notice any issues at all. 

My point about USBc was. can't you install some high-power USB chargers and run on 12v natively? (not sure how these would fayre in honesty)

 

 

[TeamElla]

59 minutes ago, FreedomBoatingHols said:

An inverter that's just on and dormant will draw very little from the batteries (unless it's a terrible design) and the load on the DC supply goes up as demand on the 240v end of the system increases. A 61 watt supply is sod all in real terms. 

 

 

Of course that's true (but a really cheap quasi sine wave inverter doesn't need to be loaded up to put out a poor copy of a sine wave AC feed)

 

With inverters, we have only been discussing operating or charging equipment from an inverter's AC output.

USB voltage is 5 volts DC, so it's a pretty simple circuit to produce a regulated 5 volts DC output from a 12 volts DC input. Cigar socket USB adaptors come to mind.

 

 

[TeamElla]

most of the cigar socket USB chargers don't go above 2.5 amps output

[TeamElla]

https://uk.rs-online.com/web/p/isolated-dc-dc-converters/0183837/