Make a Power Bank output 9V to 12v with Resistors, Diodes connected to D+ and D-

About power bank characteristics and its functionalities

In the modern-day tech world, having a dependable power source is important, in particular, whilst on the go. Power banks have emerged as a famous solution, but what if you may create your custom-designed electricity bank able to impart 12V power output?

The latest power banks are having various types of functions and can power most devices especially devices that use Type C ports like

  1. PC e.g MacBooks and other newer PCs which rated voltage from 12v to 20.5v dc
  2. mobile phones that use type c ports are rated to 5v on normal charging and 9v on fast charging mode
  3. Some power bank type A ports can also do these functions
  4. Can run most devices that run on 9v to 12v example routers and wifi, most of them are rated 12v 2A

Things needed for you power bank to work to your expectation

  • Special cables are needed for auto voltage selection: For your power bank to auto-select it right voltage you must connect it to the device you want to use with a data cable, be it type c or type A the device will communicate with the power bank and the power bank will give it the needed voltage
  • In case you want to power a device that can’t communicate or send data to the power note when there is no communication between the power bank and the device, it will output 5V because there is no communication but I will show you how.


In this step-by-step guide, we’ll show you the way to alter a USB port using resistors and diodes to generate a 12V power output. By following these instructions carefully, you may construct your own on a perf board.

Understanding the Basics

Before diving into the change system, it’s critical to recognize the simple principles. USB ports generally provide a 5V power output but can change its output due to data received from the powered device.


By making a voltage divider with resistor and diodes, we can tweak the power input to give 9V and 12V respectively.

1n4007 diode can drop 0.6v when used on zener diode mode and also a blue led can drop 3v when used as a zener diode, 0.6v is needed in pin D+ and D- with a reset tap button to activate the 12v and also D+ needs 3V and D- need 0.6v to activate 9V and also you need to tap the reset tap switch before it is activated

5V output D+ = 0V D- =0V D+ Bridged to D-
9V output D+ =3V D- = 0.6V  
12V output D+ = 0.6V D- =0.6V  

Components needed

To start with the modification, accumulate the following additives: USB cable Power bank case or enclosure Resistors (unique values can be discussed later) Diodes (specific values may be mentioned later) Soldering iron Solder wire Wire strippers Heat cut back tubing Electrical tape Multimeter (non-obligatory but advocated for checking out)

Modifying the USB Port

Disassemble the USB cable, isolating the male and female connectors.


Identify the

male type A port

typev a port

D+ (D plus)

D- (D minus)

lines inside the USB connector. Solder resistors in the collection on each of the D and D- strains to create a voltage drop. The unique resistor values will rely upon the favored voltage conversion and the current abilities of your strength supply. Place diodes in parallel with the resistors to ensure the voltage flows in an appropriate course. Insulate the connections with the use of warm cut-back tubing and secure them with electric tape for introduced protection. Reconnect the male and female USB connectors.

Female Type A port

female port

Testing and Safety Precautions

Before the usage of the electric bank, it is essential to test its capability and performance. Use a multimeter to degree the output voltage, making sure it reaches the favored 12V. Always use caution whilst working with electric additives and soldering iron. Ensure you’ve got clear information on protection techniques and suggestions. Regularly check out the strength bank for any signs and symptoms of damage or put on and tear. Discontinue use if any faults are detected. Avoid exposing the electricity financial institution to excessive temperatures, moisture, or other destructive conditions.


With the growing need for sustainable and portable power source, being able to create a custom 9V or 12V power can prove beneficial. By enhancing a USB port with resistors, diodes, switch, you can achieve the favored voltage output and meet your power requirements.


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