Running a laptop off 12V

[grazza]

Ok electrical gurus....

I want to run an old laptop (Dell L400) off 12V and I want it to use as little power as possible.

I am going to run without the screen on (folded up) and without the hard disk (USB boot to flash drive or IDE flash drive)

I may want it to drive an external display for GPS use.

The AC adapter is rated output 19V DC, 2.6A.

So do I use an inverter to step up 12V to 240V, plug in the AC adapter to then step down to 19V, or do I think of some other voltage converter circuit so I dont need the AC inverter, i.e. a 12Vdc to 19Vdc device....

My aim is to use as little power as possible since I also want to use the setup on a boat with only solar charging 100Ah battery.

thanks for any advice
Grazza

[-Scott-]

Your best bet is something along the lines of this.

DC-DC adaptor, one less conversion SHOULD be more efficient than DC-AC-DC.

DSE also sell this kit for $30, but it's rated for less than 2A at 19V. Without screen or hard drive that may be enough? How are you with a soldering iron?

Good luck,

Scott

[fpvf6]

I would recommend a 12 to 24 v inverter as the best option. I use one in the car a lot for running laptop. A 300w unit like this one:

http://jaycar.com.au/productView.asp?ID ... &SUBCATID=

They are also very handy for charging your phone using the 240v charger or running a light etc. This one is good as it's got a cooling fan.

Not sure how this would go on the boat etc...

Hope that helps.

Jonesy

[grazza]

Thanks Scott.

I am fairly experienced with soldering, although I stupidly left the iron on all day recently

I am hoping that the laptop will idle along using little power and may need to fiddle with the power management settings. There may be the rare occasion where I want to play a DVD or MPEG so I will try to measure the current drain so I dont overload the circuit.

I am hoping that using this old laptop will be a better option than building a custom mini PC.

[pcman]

try running it direct off 12v i had a old laptop that was 16v plugged it straight into 12v worked fine

otherwise jaycar sell a 12v-laptop adapter for 50bux or you can get one on ebay for around 20-30 including shipping

[HotFourOk]

Yeah, you can buy car adapters for the laptops. That's your best bet.

You would cause losses by going from DC-AC-DC as Scott said.

Something like this should work
http://cgi.ebay.com.au/Dell-HP-laptop-C ... dZViewItem