# DC adapters for laptop in automobile



## WisJim (Jan 14, 2004)

I am thinking of getting a DC adapter so I can charge the laptop in the car. Anyone have any experience with the cheap ones (under $40) available at places like eBay, or are the ones sold under the computer brand name worth the extra money ($70 to $150)?

Any suggestions based on actual experience will be appreciated.

Thanks.
Jim


----------



## Guest (Feb 3, 2009)

I bought a power inverter at the advance auto for about 25 bucks, plug into cigaret lighter to have 120 (household) current. run my laptop, charge cell phones, lamp, small tools, etc.


----------



## WisJim (Jan 14, 2004)

A small inverter was another option that I was considering, but don't like the inefficiency of the small units. Might give it a try, though.


----------



## Nevada (Sep 9, 2004)

zong said:


> I bought a power inverter at the advance auto for about 25 bucks, plug into cigaret lighter to have 120 (household) current. run my laptop, charge cell phones, lamp, small tools, etc.


I've tried a power inverter with my laptop, but it makes a buzzing sound when I make phone calls with Skype. I go on battery to make calls with my laptop now. I haven't tried a DC power adapter with Skype, but that may very will cure the buzz.


----------



## mistletoad (Apr 17, 2003)

I use a power inverter too - that's how I charge my laptop, cell phone, camera batteries, etc. I figure I'm driving anyway and I have a high output alternator - if my van battery is fully charged and I'm not losing power, why would the inefficiency of the power inverter matter? What could I be doing with that power if it wasn't being wasted due to inefficiency?


----------



## Gary in ohio (May 11, 2002)

DO go the inverter route. Just buy the laptop auto power supply. Cheaper and better for the laptop. No noise from the inverter.


----------



## Aunt Penney (May 2, 2008)

We have the type with the transformer/adapter in a little box on a long cord and two outlets, cost about $20, can plug two things in at once, only makes a beep sound when turning car on and off. I have used the computer plugged in with car off up to an hour with no problems, but beware, naively while waiting for a ferry once we had radio and computer going and car battery went dead! (fun thing on a ferry line!). Drive around with computer charging a lot - so convenient - highly recommend it and well worth the money.

We tried (someone else's) less expensive direct plug-in but the plug wouldn't fit into our van's slightly recessed power outlet (cigarette lighter). Something to consider.


----------



## mikellmikell (Nov 9, 2005)

Some cars with more than one outlet the outlet may be switched to only be on when the key is on . That would be the better one so you don't run the battery down. Converting 12 volts to 120 is a x10 multiplyer on the amps so that little box may draw more than leaving your lights on would.

mikell


----------



## lharvey (Jul 1, 2003)

I run my truck laptop off a 75 watt converter from Radio Shack. 

Can't remember the price, it is about three years old. No issues

Plenty of power to charge and run the laptop.

L


----------



## Gary in ohio (May 11, 2002)

mikellmikell said:


> Some cars with more than one outlet the outlet may be switched to only be on when the key is on . That would be the better one so you don't run the battery down. Converting 12 volts to 120 is a x10 multiplyer on the amps so that little box may draw more than leaving your lights on would.
> 
> mikell


Keep in mind an inverter draws power even if nothing is plugged in to the 110v side.


----------



## WisJim (Jan 14, 2004)

One reason that I didn't go out and buy the inverter is inefficiency, as I would not be running from a car but would be using a solar charged small battery to run the laptop. 

The intention of my original question was to get a comparison of the cheap DC adapters versus the computer name brand expensive DC adapters for a laptop. A cheapy might be $25 to $40, while a computer name brand one is $100 to $175. A typical small inverter might be 50% efficient, plus it uses the inefficient AC power supply that came with the laptop, so a DC auto adapter should be using significantly less power, as far as I can see.


----------



## HermitJohn (May 10, 2002)

Its only way I have stayed online week since ice storm here, I still dont have electric though have had two fires from stupid linemen not taking time to check for downed lines. Fire dept people and state forestry people may finally have made an impression on power company people but only time will tell.

Anyway mine is just an el cheapo universal 12V power supply for laptop, you set little dial to voltage you require and then use plug adapter. I had bought it some years ago for a long now defunct laptop. Very cheap, less than $15. When got my current laptop, I couldnt find the extra plug adapters so looked in my box of orphan power bricks and found an end that fit currennt laptop, clipped the end off and spliced the wires. Works fine though it looks like reject from dollar store and has held up fine. Think it was a Fellowes brand if that means anything. 

Now my 12V cell phone charger cable quit after two days and for it I am getting an OEM 12V cable off ebay. Until then dug out a usb charging cable for phone, just makes life difficult, as its slow and to charge I have a car alternator hooked to a smokey old lawn mower engine charging battery out of my truck with laptop powered off that and the usb cable plugged into the laptop. McGiver would be proud.


----------



## WisJim (Jan 14, 2004)

Hermitjohn, that sounds like the kind of adapter I was looking at. I may just buy one on eBay and see how it goes. Thanks--and best of luck in the ice!!


----------



## radiofish (Mar 30, 2007)

For my Dell laptop, I looked at the close to $100 dollars factory DC adapter. Well, that's kind of steep of a price..

So instead, I went on Ebay and got a Lund brand DC charger for the laptop. Besides the standard 12VDC cigarette plug adapter, it came with the airlines funky DC power jack adapter also. All in a nice zippered pouch at $23.00 dollars including shipping and handling..


----------



## HermitJohn (May 10, 2002)

Update. Past two weeks been without electric (its on now). One night hooked clips to battery and got wrong polarity, well the magic smoke genie espcaped from my Fellowes adapter. Should have just burnt fuse but genius here sometime when I used it in past replaced glass fuse with an automotive fuse that didnt burn through quick enough, then never bought the correct fuse. 

My old laptop battery totally discharged. So went over to friends house and spent some time looking for a replacement. Bought two off ebay, one a fancy OEM Dell unit ($12 total shipped price), the other some 3rd party thing about like I had ($8 total shipped price). Both were dedicated adapters and had weird plug ends that plug into one specific brand/model computer, but both put out the necessary 18-20V and 3.5+A. The Dell unit must have been really high dollar when new, big heat sink, fancy looking, not looking like plasticky dollar store reject. I just spliced end off my old adapter. It works great.

The old Fellowes cheapie looking universal adapter worked fine until I destroyed it, but that Dell adapter really impressed me, think in future I'd look for a simular OEM style adapter that otherwise meets electric needs and splice on plug that matches my laptop.


----------

