HomeHardware


In Vehicle Power for Laptop PC
Brian Conner
There is probably a more appropriate forum for this, but based on the activity in this one, I thought I'd stand a good chance of receiving an answer.

I've been using Streets & Trips w/o GPS for many years and just recently purchased S&T 2010 w/ GPS to use with a recently purchased Windows 7 laptop.

For long trips, the (4 hour) laptop battery won't last long enough for a 10 to 12 hour day, so how can I power the laptop for an entire day? I'll be taking a 1345 mile trip (1345 miles each way) soon in my 2000 Dodge Grand Caravan. It has a 12v DC power outlet, but I've heard this isn't a good source of power for a laptop computer.

Is there a solution to this power problem?

If that 12v outlet is a good solution, where can I find an appropriate cable for my Asus laptop?


Brian Conner
tcassidy
The most versatile solution is an inverter which provides 110v ac from the 12vdc outlet. They are inexpensive and reliable as long as the rating is more than the power brick for your laptop says it needs.

Take a look at some of the threads listed below for more discussion on this topic.

Terry
Brian Conner
Thank you, tcassidy. That is the solution.

Based on a quick bit of research, it seems the preferred hook-up is direct to battery, but that job is beyond my skills, so it would be an extra cost to have a shop do that for me.

My van has a 12v outlet in the front, rather than a cig lighter outlet, and the inverters I've just looked at have the lighter plug. Do you know how I can bridge that gap? An adapter cable? Or would an inverter's lighter plug go right into the 12v outlet just fine?

My laptop PS says it's 65 watts, so using the 12v outlet with its 80-100w limitation would seem to be adequate.
tcassidy
What kind of 12v outlet does it have? I thought the cigar lighter plug/ socket was standard.

Terry
Brian Conner
I just spoke with the guy at the service dept at the local Dodge dealer and he said I can plug a lighter plug directly into that 12v power outlet, so my worry was not justified.

I'm good to go. Thanks you very much, Terry. You helped me tremendously.


Brian
malaki86
The only time you need a power invertor hooked direct to the battery is when they're large. I've got invertors up to 400 watt that are cig lighter hookups. Over 400 and you'll want it direct. I can run my entire laptop system in my truck on a 200 watt invertor, and that includes the laptop, a wired usb hub and a multi-function inkjet printer.

With the 1,500watt invertor I currently use, I can run a microwave, a hair dryer, etc on it (just not all at the same time).
Brian Conner
Thank you for clarifying that point.
Marvin Hlavac
Brian, the following is a good discussion on the topic. Info there may be of use to you, too (but is seems like all your questions might have already been answered in this thread).

http://www.laptopgpsworld.com/726-choosing-power-inverter-your-laptop
Ken in Regina
Brian, just another small thought. If the only thing you want to run is your laptop, and it sounds like that's the case, the cleaner solution is the 12V adapter for your laptop. There is no reason I can think of not to use it.

If you are concerned about the power draw on the 12V power outlet, you are thinking the wrong direction. Getting an inverter increases the power requirement substantially, versus using a 12VDC adapter. The inverter is taking 12V DC (direct current) power and "inverting" it to 120V. In addition it is having to simulate alternating current (AC). That is an inefficient process.

Then you are running the 120VAC power from the inverter through the power brick which converts the power back to DC at, usually, around 19V. That's another inefficient process.

With the 12VDC adapter, the current stays as direct current (that's what your laptop drinks) and all that gets adjusted is the voltage, from 12V up to whatever voltage the laptop takes (19VDC or whatever).

That's a much less inefficient process .. very little loss involved.

And you have a much cleaner connection .. a single cable to run between the power outlet and the laptop versus a cable to the inverter, a cable between the inverter and the power brick and a cable from the power brick to the laptop.

Something to consider if you do not have any actual AC appliances you want/need to operate in the vehicle.

...ken...
Brian Conner
Sounds great, but I can't find one online.
Ken in Regina
Quote:
Originally Posted by Brian Conner
Sounds great, but I can't find one online.
What make and model is your laptop?

...ken...
Brian Conner
Asus K50.
tcassidy
I have this one which would do the job. However, I know there are less expensive models available.

Belkin : Travel Power Adapter

Terry
Brian Conner
Thanks for that, Unfortunately, they don't have the tip for my Asus K50.
tcassidy
I see it isn't on the list but I bet they have one. 19 volts is not uncommon and your connector is probably a barrel type tip. If interested, just email them.

Terry
laptopgpsworld.com About