While using your laptop in the car, you don’t have to worry about your laptop battery dying. Charging your computer with your car’s DC power jack (cigarette lighter) is easy.
First, you’ll need to figure out how much power your laptop uses. This can frequently be found on the bottom of the laptop, sometimes near the battery. If you don’t see it, you can find your particular model on the manufacturer’s website. The power consumption should be listed.
What the numbers mean: If the power consumption number you got was in Watts (W), you’re good to go. If not, you need two numbers, Volts (V or Vdc) and Amps (A). Multiply those two numbers together to get the power consumption in Watts.
Next, you need to get a power inverter. This device takes the electricity that comes out of the car’s power port and converts it to something similar to what comes out of the wall at your house. The below table helps you choose an inverter based on the power used by your laptop.
0-80W: Duracell Pocket Inverter 100. $25
80-130W: Duracell Pocket Inverter 175 $30
130-160W: Duracell Digital Inverter 200. $32
160-320W: Duracell Digital Inverter 400. $25
Plug the power inverter into your car’s power port. Connect your laptop to it (a surge protector is recommended), and it will charge just like it’s plugged into the wall.
PRECAUTIONS: Cars’ electrical systems are inherently less safe than your house’s. I recommend using a surge protector, just in case. I use a little one like this . Power surges are most likely to come when you’re turning the car on. Be sure to unplug your inverter from your car while you start the car. Do not charge your laptop for very long without the engine running. Doing so will drain your battery (it will be fine if you charge while the engine is going, though).
NOTE: This guide written considering standard US 15A/125V/60H wall current. Please take into consideration your country’s, car’s, and laptop’s electricity specs.