0Molten Boron 11 years ago Look at the power converter cable for your laptop. The boxy part should say what DC voltage it puts out. You'll want a voltage regulator rated at that voltage. Get a solar panel that gets really close to that voltage and a lot fo current, and connect it to the voltage regulator, and the regulator to the laptop. As long as your laptop has that correct voltage going into it, it will use its internal charging circuits to properly charge its batteries.