Emergency Mobile Charger using DC motor [Complete Guide]

Emergency Mobile Charger using DC motor

Looking for a way to charge your phone when you are completely out of options? Make yourself a emergency mobile charger or rather a portable mini generator which could come handy especially while traveling or while outdoor camping. This is a hobby project which can be made by anyone following some very simple instructions. The charger works on the principal of DC motor being used as a generator converting mechanical energy to electrical energy, if you are wondering how a DC motors works, click here. Since the voltage required by a phone is 5V a voltage regulator IC 7805 is used to get the desired output voltage from the DC motor.

This DYI project is also featured on world's best DYI website Instructables, here is link.

Items Required


DC motor


USB cable

Voltage regulator IC 7805

voltage regulator

How the Emergency Mobile Charger work ?

When the shaft of the DC motor is rotated a DC voltage is induced at the terminals. But since its not possible for a human being to maintain a constant RPM of the shaft the output voltage of the motor keep varying at some time going beyond 5V which is above the save limit of the phones. Thus an IC 7805 is used to regulate the voltage and to make sure that we have a constant 5V.

Steps to follow : 

  • Cut out the female end of the USB cable clip of the data cables. We require only RED and BLACK wires as shown in the picture :  
Mobile Charger USB cable wires
  • Now using a solder iron make the following connections as given below : 
Mobile Charger connection
Mobile Charger connection
Mobile Charger connection
Mobile Charger connection
  • Paste the IC 7805 and female USR port on the surface of the motor using a glue gun so as to secure it on the surface. You can refer the video for more information here.
  • Use a right angled iron rod at the shaft as handle for the ease of rotation. 
  • Bingo ! now you are ready to test your 'Emergency Mobile Charger' ! 


Here is a short video showing step  by step procedure : 

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