Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 18-04-2011, 17:02   #31
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Re: Running a Laptop Without an Inverter

Quote:
Originally Posted by Weyalan View Post
We are only using the inverter when we are motoring, for now.
huh? you have no house batteries? What makes you think a DC-DC converter will change so that you can use it without running the engine? We're talking about very small DC draws for a laptop (and probably charging it's battery), right?

For the posters who state that the draw is double while using an inverter... check your draw with the inverter on but without the laptop connected (idle draw from inverter). I am sure that a laptop with it's AC adapter draws less power than with a DC-DC converter. It's just how do we create that AC power source and at what efficiency. Improving that efficiency has a positive effect for all your AC powered appliances aboard while using a DC-DC converter for a laptop only helps for that laptop.

cheers,
Nick.
__________________

__________________
s/v Jedi is offline   Reply With Quote
Old 18-04-2011, 17:17   #32
Registered User

Join Date: Feb 2009
Location: NY
Posts: 243
Re: Running a Laptop Without an Inverter

DC Power Adapters for Dell Computers

Not just Dell, a lot more....
__________________

__________________
arjand is offline   Reply With Quote
Old 18-04-2011, 17:22   #33
Commercial Member
 
Mark Johnson's Avatar

Cruisers Forum Supporter

Join Date: Sep 2009
Location: New Bern NC
Boat: Searunner 34 Trimaran
Posts: 1,565
Re: Running a Laptop Without an Inverter

Quote:
Originally Posted by s/v Jedi View Post
huh? you have no house batteries? What makes you think a DC-DC converter will change so that you can use it without running the engine? We're talking about very small DC draws for a laptop (and probably charging it's battery), right?

For the posters who state that the draw is double while using an inverter... check your draw with the inverter on but without the laptop connected (idle draw from inverter). I am sure that a laptop with it's AC adapter draws less power than with a DC-DC converter. It's just how do we create that AC power source and at what efficiency. Improving that efficiency has a positive effect for all your AC powered appliances aboard while using a DC-DC converter for a laptop only helps for that laptop.

cheers,
Nick.
I was talking about using the 12VDC to 19VDC car adapter with cigarette lighter plug, to say... watch a movie. It is half as many Ah to do so, vs if I used the inverter to create 120V and then reduce that to 19V DC with the factory supplied AC black box.

I use the DC to DC converters to avoid the load from having the inverter in use at all. Compared to the inverter way of doing it, (shutting the 120V inverter off), and using DC to DC converters to run 19V appliances, uses a bit less than half as many Ah.

I measured with my "Link 10", with all charges in or out off, except the TV.

We avoid the use of our inverter except occasionally, to charge nicad batteries and the like. Inverters are very inefficient ways to do it.

Mark
__________________
Mark Johnson is offline   Reply With Quote
Old 18-04-2011, 21:46   #34
Senior Cruiser

Cruisers Forum Supporter

Join Date: Nov 2005
Location: Tasmania
Boat: VandeStadt IOR 40' - Insatiable
Posts: 2,317
Images: 91
Re: Running a Laptop Without an Inverter

Sure we have batteries - 2 x house at 100AH each (and 1 x engine which is less AH but more cold cranking amps), but I am so suspicious of "electrickery" I try not to use it unless I has to!
__________________
Weyalan is offline   Reply With Quote
Old 19-04-2011, 00:30   #35
Registered User
 
sctpc's Avatar

Join Date: Jul 2008
Location: Melbourne Australia
Boat: saga kan walker 31ft
Posts: 545
Send a message via Skype™ to sctpc
Re: Running a Laptop Without an Inverter

Watch this item

AU $18.99+AU $9.99Time left:13d 6h 5m HP CAR ADAPTER COMPAQ 19V 4.74A Presario V3000 V6000
Location: Australia

Feedback: 2,109 | 99.8%

Watch this item

AU $18.99+AU $9.99
__________________
May there always be water under your boat,

sctpc is offline   Reply With Quote
Old 19-04-2011, 01:26   #36
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Running a Laptop Without an Inverter

Quote:
Originally Posted by s/v Jedi View Post

For the posters who state that the draw is double while using an inverter... check your draw with the inverter on but without the laptop connected (idle draw from inverter). I am sure that a laptop with it's AC adapter draws less power than with a DC-DC converter. It's just how do we create that AC power source and at what efficiency. Improving that efficiency has a positive effect for all your AC powered appliances aboard while using a DC-DC converter for a laptop only helps for that laptop.

cheers,
Nick.
Nick you make a good point about the idle current of the inverter. If the inverter has to be on anyway to operate other devices the power savings using a DC to DC converter for the laptop will be less.
The DC to DC converters, however, are still typically a bit more efficient than an inverter.
__________________
noelex 77 is offline   Reply With Quote
Old 19-04-2011, 06:59   #37
Registered User

Join Date: Apr 2011
Location: MEDITERRANEAN
Boat: MAXUM 4600 SCB 46FT
Posts: 2
Re: Running a Laptop Without an Inverter

Quote:
Originally Posted by SV Escape Plan View Post
I am trying to find a "car charger" for my laptop but am not having much luck so far. I currently use the inverter to run the laptop but would prefer to go to a DC source. I have a Gateway FX series laptop whose power supply says 19.2 Volts DC 6.4amps I believe. Went to best buy and they just wanted to sell me an inverter did not understand what i was looking for. When I try the online stores none seem to recognize my "FX" series. The all suggest MX and other Gateway series. Perhaps someone here with bettter search skills can point me to a DC laptop plug for my FX series Gateway?

Also was out on the boat yesterday and tried charging my iPhone via the AC plug and inverter. It was not enough draw to kick on the inverter so will stick to DC charger there too.
Just check the web page that I have found for DC to DC converters. I am sure there should be much more :

http://www.powerstream.com/ADC.htm


Best of Luck

filipo
__________________
Filipo is offline   Reply With Quote
Old 19-04-2011, 07:23   #38
Senior Cruiser
 
AfterHoursNLCT's Avatar

Cruisers Forum Supporter

Join Date: Nov 2010
Location: Quaker Hill, CT (just above the US Coast Guard Academy)
Boat: Silverton 34 Convertible
Posts: 190
Re: Running a Laptop Without an Inverter

Quote:
Originally Posted by HappySeagull View Post
Weyalan...is it a DELL? I know many of these have a third wire at the dc jack...Perhaps other makes do too,nowadays.They can likely be tricked but....
That's what I was thinking (a Dell). They can be fooled into using a conventional power supply but you'll need to Google it to find out how (I think it involves jumping the sensor line with a resistor).....LL
__________________
AfterHoursNLCT is offline   Reply With Quote
Old 19-04-2011, 07:35   #39
Senior Cruiser
 
AfterHoursNLCT's Avatar

Cruisers Forum Supporter

Join Date: Nov 2010
Location: Quaker Hill, CT (just above the US Coast Guard Academy)
Boat: Silverton 34 Convertible
Posts: 190
Re: Running a Laptop Without an Inverter

Found this on the web....

"Well the "smart-pin" adapters have 3 connections, here's a picture of the socket:

wwwtelefonicanet/web2/informatica/skt.jpg

Ground is on the outside as normal, +19 volts on the inner ring and the center is where the "smart-pin" goes.
If you only apply power to the inner & outer rings the computer will not power up. You need to apply +19 to the center pin as well.
According to HP "The Smart technology signals the power rating and if maximum rating of the adapter is reached, the notebook will reduce its power consumption"."
__________________
AfterHoursNLCT is offline   Reply With Quote
Old 19-04-2011, 17:19   #40
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,198
Re: Running a Laptop Without an Inverter

Quote:
Originally Posted by Mark Johnson View Post
I was talking about using the 12VDC to 19VDC car adapter with cigarette lighter plug, to say... watch a movie. It is half as many Ah to do so, vs if I used the inverter to create 120V and then reduce that to 19V DC with the factory supplied AC black box.
Exactly. My argument is that half the load you see while using the inverter is actually the idle power consumption of the inverter. If it's a lot of Ah, you can improve that with a more efficient inverter. On the other hand, if you need the inverter for something else anyway, it's doesn't matter and roughly both options use same power.

Quote:
Originally Posted by Weyalan View Post
Sure we have batteries - 2 x house at 100AH each (and 1 x engine which is less AH but more cold cranking amps), but I am so suspicious of "electrickery" I try not to use it unless I has to!
Okay, you are on very low power with the 200Ah house bank. I agree you can only use the computer while motoring.

Quote:
Originally Posted by noelex 77 View Post
Nick you make a good point about the idle current of the inverter. If the inverter has to be on anyway to operate other devices the power savings using a DC to DC converter for the laptop will be less.
The DC to DC converters, however, are still typically a bit more efficient than an inverter.
Exactly. I'm afraid my argument is a bit too technical and hard to follow so it's good to see your msg

I always have this other argument: if you need to do things like this you should use a (miniature) desktop computer instead of a laptop. It's crazy to charge a (laptop) battery from your house battery. It's also very power inefficient. Think of the combination of house batteries and a small pure sine inverter as a "on-line type" UPS and use that to power a MacMini instead of a MacBook

ciao!
Nick.
__________________
s/v Jedi is offline   Reply With Quote
Old 20-04-2011, 09:27   #41
Registered User
 
HappySeagull's Avatar

Join Date: Dec 2010
Location: B.C.,Canada
Boat: 29'
Posts: 2,395
Re: Running a Laptop Without an Inverter

Quote:
Originally Posted by AfterHoursNLCT View Post
Found this on the web....

"Well the "smart-pin" adapters have 3 connections, here's a picture of the socket:

wwwtelefonicanet/web2/informatica/skt.jpg

Ground is on the outside as normal, +19 volts on the inner ring and the center is where the "smart-pin" goes.
If you only apply power to the inner & outer rings the computer will not power up. You need to apply +19 to the center pin as well.
According to HP "The Smart technology signals the power rating and if maximum rating of the adapter is reached, the notebook will reduce its power consumption"."
AfterHours,Thanks for tracking that down!That's a help!I didn't know how general it was per other laptops too...
__________________
HappySeagull is offline   Reply With Quote
Old 20-04-2011, 09:42   #42
Registered User
 
HappySeagull's Avatar

Join Date: Dec 2010
Location: B.C.,Canada
Boat: 29'
Posts: 2,395
Re: Running a Laptop Without an Inverter

mmm,well there's one thing I don't like about my 30$ xantrex inverter is the radio noise,but idle current draw is VERY low.
Inverter+T42
nothing plugged in =.06amp
JUST ac adapter plugggedinto lap =.25
running lo brite =2.04
running hibrite screen =2.62

and here is the laptop connected DIRECT to the Boat Battery-I mean,REALLY direct,where the 10.8v laptop battery supplies it....
IBM T42 startup max=2.7ampsmax
idle lobrite=1.6amps
idle hibrite=1.8amps
suspend=0.04amps
All powersaving schemes are always disabled on my machines...except closing the lid and adjusting brightness.

roughly,half an amp burned by the inverter.
__________________
HappySeagull is offline   Reply With Quote
Old 20-04-2011, 11:08   #43
Senior Cruiser
 
Lancerbye's Avatar

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Ladysmith,BC, Vancouver Island , Canada
Boat: Lancer 44 Motorsailer
Posts: 1,757
Images: 32
Re: Running a Laptop Without an Inverter

I am finding this discussion interesting and amuzing. If you wish to use a DC to DC converter instead of an inverter you are in effect using an inverter with a dedicated output. Inside the converter is a low current inverter, a transformer and a rectifier. They are just small and limited in use for a single purpose.
__________________
The basis of accomplishment is in never quitting
Mengzi Meng-tse
Lancerbye is offline   Reply With Quote
Old 20-04-2011, 11:40   #44
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Running a Laptop Without an Inverter

Quote:
Originally Posted by Lancerbye View Post
I am finding this discussion interesting and amuzing. If you wish to use a DC to DC converter instead of an inverter you are in effect using an inverter with a dedicated output. Inside the converter is a low current inverter, a transformer and a rectifier. They are just small and limited in use for a single purpose.
As you point out to convert the voltage both a DC converter an inverter have to go through an AC stage, but that is where the comparison ends. An inverter has to produce a very specific voltage, frequency and even shape. In a DC converter the AC characteristics are open and the electronic engineer can use whatever voltage and frequency is most efficient (and cost effective)

No matter what the reason I have yet to see a DC converter that’s not more power efficient than an inerter and saving power is important for most cruising boats.
__________________
noelex 77 is offline   Reply With Quote
Old 20-04-2011, 11:43   #45
Registered User
 
HappySeagull's Avatar

Join Date: Dec 2010
Location: B.C.,Canada
Boat: 29'
Posts: 2,395
Re: Running a Laptop Without an Inverter

Quote:
Originally Posted by Lancerbye View Post
I am finding this discussion interesting and amuzing. If you wish to use a DC to DC converter instead of an inverter you are in effect using an inverter with a dedicated output. Inside the converter is a low current inverter, a transformer and a rectifier. They are just small and limited in use for a single purpose.
...that's what I surmise(not having one but guessing they must convert to AC anyways and opinions here back this up!)...I mean,these dc/dc converters seem expensive for what they do.
Compare..

dc/dc is: BoatDC -->[DC/DC adaptor internal...AC-->rectified and regulate]--->LaptopDC

inverter is:BoatDC-->[Inverter internal..AC]-->[laptop adapter internal rectify and regulate]--->LaptopDC

It seems outwardly like saving an saving efficiency "step" but is not, in fact.
Those that are having huge drains at the inverter,I'd suggest getting a 200 -300 watt one for 20-30$...but,I'm standing by for opposing data!

That said,there IS a simple way without the "loss".Add a 6 volt battery to your boat bank or use 4 as optional 12,18,24 supplies...18 runs many laptops,I bet.(12 runs a few..)The 24 could be regulated down fairly easily but of course the 4-5 volts burned off is waste,i guess.oh well.
__________________

__________________
HappySeagull is offline   Reply With Quote
Reply

Tags
inverter, laptop

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Inverter Running Despite Absence of Load hummingway Electrical: Batteries, Generators & Solar 16 10-11-2010 10:43
Calculating Amps Drawn Before Inverter and After Inverter ? impi Electrical: Batteries, Generators & Solar 23 26-09-2010 23:24
Running a Laptop Efficiently dennisail Marine Electronics 24 25-05-2010 10:08
asus laptop running seaclear scotty Navigation 7 16-10-2008 10:16
Running a laptop from 12 volt supply Dunkers Navigation 12 09-08-2006 11:19



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 13:46.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.