How to build a wind up power supply for a laptop

Updated April 17, 2017

Mechanical windup power produces such little electricity that it can only be put to use in a handful of cases. Recharging notebook computers is one of the few tasks that requires such little power that a crank generator can adequately meet the power requirement. The smaller and more efficient the laptop, the easier it will be to charge. With a modified 12v drill as the hand-crank power source, your laptop can be up and ready to compute.

Remove the battery from the drill, and place it aside. This won't be used for this project, but you may wish to save it in case you ever wish to use the drill again. On the wire leads that connect the drill to the battery, identify the positive and negative wires. If in doubt, check the markings on the battery, or test the charged battery using the voltmeter to determine which terminal is positive and negative. Now, connect wires to the positive and negative leads. You can use alligator clips if you don't want to damage the drill by splicing into the lines.

Connect the opposite ends of the positive and negative leads to the car cigarette-lighter plug-in adaptor. This will give you a 12v outlet to plug any DC device into. Install a 10 amp diode between the drill and the outlet. This acts like a one-way valve to prevent the drill from attempting to use the laptop's battery power to spin itself. You may also wish to wire your voltmeter in serial with the flow of power to measure how much electricity your cranking is producing.

Plug your DC to AC power adaptor into the cigarette lighter outlet. This will provide a normal, household style, 120v electrical socket to plug small appliances into. Any other device that has a 12v power outlet such as a cell phone charger can also be hooked up to the cigarette lighter outlet, avoiding the need for an inverter.

Using tape or zip ties, compress the button on the drill all the way down, then secure it into place. Power will not flow unless this trigger button is depressed at all times. If you don't have a diode installed, the drill may try to spin at this point, making it impossible to be used as a crank generator.

Attach the old-fashioned manual drill into the end of the power drill. This can usually be inserted just like a drill bit, then clamped down upon by the drill. The power supply is now complete. Simply turn the inverters switch on, plug the laptop in, and start cranking away. The drill will act as a generator, sending DC power to the inverter, which is then converted into AC power to charge the laptop.


The drill can also be used to charge a battery, to store the power for a later time.


Watch the voltmeter closely to make sure you're not producing too much power for the inverter to handle.

Things You'll Need

  • Any 12v power drill
  • Old-fashioned hand drill
  • DC to AC inverter rated at 120 watts or more
  • 10 amp diode
  • Voltmeter
  • Car cigarette-lighter plug-in
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About the Author

Ryan Bauer is a freelance writer located in Ozark, Missouri. He has written numerous articles and books, including "How to Improve Your Credit Score 100 Points in 100 Days." Bauer is an experienced automotive mechanic and computer technician.