How do you power a laptop from your car lighter outlet?

[hurtstotalktoyou]

Hey, all.

I'm about to buy a Compaq C770US laptop ($500OTD, $470AR) for use in my car. Each day it will be used for an approximately four-hour period, mostly to watch videos. Obviously, the battery will only get me so far in this capacity. So, I'm either going to need to buy a backup battery, or else buy a power converter to power the laptop from the electric lighter socket.

So, how would I do that? Assuming my car battery can handle the drain, what do I need to buy to connect the C770US to the lighter socket?

Would a power inverter from Wal-mart work? If so, what kind of wattage do I need? E.g., would this 75W inverter be sufficient? How about this 200W inverter?

Any suggestions would be much appreciated. Thanks!

 

[996GT2]

You need to check the AC adaptor on your laptop. Some laptops with integrated graphics and less power hungry processors run fine off 65w AC adaptors, while other laptops need 90w+. Depending on what you have, a 75w inverter might work, but you would be completely safe with the 200w.

 

[corkyg]

When I travel, I use a dedicated travel power module for my Lenovo T60. It comes with a lighter adapter, airline adapter, and A/C plug. Input can be AC or DC. It is rated at 4.55a @ 20VDC, and that equals 91 watts.

As was stated above, you need to look at the decal on your A/C adapter to determine what your system needs. The 200w inverter would work for sure. The 75w might be marginal.

 

[kyzen]

I do hope you're not watching the videos while driving 😉

Your laptop though uses a 65w power supply, so the 75w inverter would suffice.

 

[corkyg]

Originally posted by: kyzen
I do hope you're not watching the videos while driving 😉

Three years ago I was driving from Tucson to L.A. Just out of Blythe on I-10 West, I passed a car that was not really steady in the lane. As I went by (as quickly as I could) I saw the driver reading a book held on top of the steering wheel.

These days, stupidity knows no bounds. 🙂

 

[heymrdj]

I used my laptop as a 40GB MP3 player for my 3,000 mile round trip this summer. I have a 300W continuous, 500W peak inverter in my truck connected to a 25 amp (actually wired for this, not just fused to it) 12V point. It can charge me and my brothers DV 6500t and 9550t laptop at the same time with the engine off. But it cannot get enough battery power to run them with lids open (the inverter starts beeping telling me low voltage). It can run his fine alone on battery, and it can run mine alone fairly well, but if I game it again sets off the low voltage alarm on the battery. What i'm getting at is as important as the inverter is, your car's electrical system matters big time if you don't have 14.4v alternator power going to the inverter instead of 12v battery power. Alot how like a car stereo amplifier can make hundreds of watts less than rated without the engine on because it's feeding on 12v instead of alternator 14.4v.