Mobile Power

[howdy76]

So, I'm looking to be able to run/charge my laptop in the car and was wondering if there's any reason I can't use one of those $20 adapters that converts the DC power from the cigarette lighter into 110v AC?

[kent1146]

Those would be fine, but I thought they were much more expensive (in the neighborhood of $100?). If you can get one for $20, go for it.

Another option for you is to buy a 3rd party laptop power supply that can plug into 12V DC. Some designs allow only for 12V DC in cars. Other designs have switchable power sources, so a single power brick can be plugged into an AC outlet, a 12V DC car cigarette power socket, or an airplane power socket.

[ua549]

There is no point in converting DC to AC and then back to DC.
Just buy a normal car/air power adapter for your laptop.
Also make sure that whatever you get has sufficient wattage to run your notebook.
There is a amperage and/or wattage label on your current notebook adapter for both input and output.
For example my power adapter requires 1.5 amps of 120v AC power as input and outputs 4.02 amps of 19.5v DC power.
Another possibility is to simply carry a spare battery to extend run time.

[kent1146]

I agree that going DC to AC to DC is highly inefficient. However, I do see some benefits there. If the OP can really get a converter for $20, it would be a lot cheaper than buying a new adapter. Furthermore, a converter could have much more utility to power other devices versus a dedicated laptop charger.

[howdy76]

Something like this.

http://www.bestbuy.ca/en-CA/product/...208cb2637ben02

I will check the power requirments for my laptop but my thinking was since the little box on the powercord converts the ac power to DC I didn't have to worry about things like Sine wave vs. Modified Sine etc.

[ua549]

I doubt if 75 watts is enough to run a notebook. Mine requires 180 watts.
What does the power supply label say about AC input requirements?

[howdy76]

The transfomer on the power cord lists input power at 65 watts (1.5 amps)
Output DC power at 3.34 amps

There's a couple of others in that $50 range that run up to 300 watts so they may be a better value

[ua549]

1.5 amps of 120v AC is 180 watts. Amps multiplied by volts equals watts.

Some power bricks are rated at lower voltages than 120 such as 110 or 100.

For $50 you can get a universal Auto/Boat/Airplane DC-DC power adapter for a notebook.
Depending on you model notebook, 12vDC power adapters cost less than $20 at buy.com.