DIY 60W PD Power Bank With Arduino Real Time Battery Info Display

Recently, I was planning to get a 60W PD power bank for my laptop so that I don't need to worry about my laptop running out of battery during lectures. However, all the 60W power bank on the market are bulk and expensive. That is why I decided to make my own.

While I was designing the power bank, I thought to myself, why can't I make one with a real time battery display? That is why I started this project: A 60W PD power bank with real time battery information display!

Supplies

To make this power bank, you will need some general parts that you might have already lying around in your home workshop.

• 10K resistors x 2
• 10K variable resistors x 2
• 5.1V zener diode x 2
• Arduino nano
• prototyping boards
• 3D printer
• M2x5 screws x 4
• soldering tools
• buck converter (16.8V -> 5V)
• ACS712 (5A)
• power switch

However, you will also need to get some unique parts, which includes

• UART HMI display (The one I am using is 2.2 inch)
• 4S (14.8v) Lithium Ion Battery (I am using 4 x Panasonic 3200mAH cells)
• 60W IP2716 based power boost & charging module

Step 1: Voltage Divider & Buck Converter

First, you need to make the voltage divider for the Arduino to read the voltage from the battery and the type C output port. The diagram is attached in the images above. Following the configuration in the photos, you can make it really small and it should be able to fit in a corner next to the green buck converter which covert the 16.8v battery voltage into 5V for the Arduino.

Step 2: ACS712

Next, connect the ACS712 sensor as described in the picture. Notes that you would want to get the 5A version of the sensor instead of the 10A or 20A versions. After finish, glue this to the back of the HMI display

Step 3: Program the UART HMI Display

Then, you can download the UART HMI Studio tool from the HMI display supplier and program it. The one I am using was from a manufacturer named "Taojingchi" and they have offer me the interface editor where I can download from here. But notes that your HMI displat might be from another manufacturer and they should have their own software for editing the UI.

After finished editing the code and uploaded the interface to the UART HMI display, unplug the display from your PC and connect it to the Arduino nano's pin 2 and 3 for its Software Serial.

You can find the zip file for the interface code attached here as a pdf file. Download the pdf file and rename its file extension to .zip, unzip it to get the source code for my interface.

Step 4: Program the Arduino Nano

Next, edit the code based on your configurations and upload the following code to the Arduino. Fields that you might need to change includes

• currentCalibrationOffset (The offset current for your current sensor)
• debugMode (Set to true if you want to test the code without the HMI display)
• HMISerial.begin(9600) (Change this line if your HMI display doesn't runs on 9600 baudrate)

Step 5: Finalizing the Information Display

After all the wiring and program are uploaded, glue everything together and supply a voltage on 16.8V on the battery+ and a 20V on the out+ pins. You should be able to see the information displaying correctly. If not, try adjust the variable resistor so that the voltage on the screen matches your lab bench power supply output. For the current testing, you can observe the difference between your power supply and the displayed information and adjust the offset value in Arduino code manually.

Notes: You should get the power for the buck converter from the BAT+ wire instead of the current sensing wire that runs through the ACS712.

Step 6: 3D Printing Case

Then, you can start 3D printing the case. You can print all of them in single color but don't you think adding a purple layer in between makes it feel really amazing?

Step 7: Seal Up the Display & Arduino

After the printing is done, you can use the screen cover and the black plate to seal up the screen unit with the Arduino and current sensor.

After this stage, you should only got a few wires exposed, they should be

• BAT+ (Battery + terminal, also use as powering the buck converter)
• OUT+ (Type C output port)
• GND
• Current Measure Input
• Current Measure Output

Step 8: Connect the Battery and PD Power Board

After that, connect the battery to the power switch, PD power board and the information display as follows.

Step 9: Done!

Lastly, seal it up and turn it on, your unique 60W PD power bank is now ready to use!

Comments

[johnchen40904]

Just wondering, how much power does the Arduino and display draw?
BTW 3rd image of Supplies... mikochi approves www

[tobychui]

The Arduino and display draws around 0.2 - 0.3W. The buck converter I used claim to have a conversion rate up to 97% but I didn't really test it out. I assume the whole display unit should draw less than 0.5W ... nye.

[Zero2019]

Any way you can modify this so it could be charged from a wireless charging pad?

[tobychui]

In theory you can attach a wireless charging module to the side of the power bank and connect its output (5V, I assume) to the type C input port with a diode internally.

[Zero2019]

Okay because so far they've gotten it to the about 5 volts but about 30 watt charging capacity for some of the newer systems that they are using for the wireless charging assembly

[mrbonine]

First, this is absolutely beautiful! As a guy who generally eschews the way a protect looks focusing more on how it works you've maximized both brilliantly. One question on your choice of batteries: for nearly any project using batteries I only buy LiFePO4. Did you consider these?

[tobychui]

Thanks but no, LiFePO4 has lower energy density then LiPo which will makes the power bank much larger for the same capacity. Besides, most PD protocol boards are designed for LiPo voltage only.

[natoqc]

This is an interesting project, being a novice it is not clear to me how the power bank is charged? If I understand well it is necessary to have a 16.8v power supply, but where is it plugged in? I am presuming the USB-C port is only power-out...
How long does the Power Bank take to charge?

[tobychui]

Hi, the type C port works as both the charging and discharging port at 60W Max. For the board I use, it can step up the voltage from any type C supplied voltage and charge the battery. So if you use 5V 3A to charge it (15W), it might take much longer than using a 20V 3.25A (65W, fully charged around 45 min) PD charger to charge it up fully.

[danielmadrid19]

Nice!!.

I've missed the fast charge feature and I think that display is a bit overkill to this kind of projects, but it's a good project to power Arduino based electronics.

[hatem0]

Hi,
The interface.pdf is not working and I wonder if it is easy for your to put a circuit diagram for the whole project as a whole.

[tobychui]

Hi!
As what I have mentioned in the instructable, you will need to download the pdf and rename its file extension to ".zip" from ".pdf" to works (Instructable no longer allow uploads of zip files so this is the only way to go).

You can see the attached image for the overall circuit. Depending on your PD control board type and layout, you might need some minor adjustment on how to get the BAT+ and VOUT (Type C output) voltage from the board, but the idea is basically the same.

[x893]

Hello,
awesome project !
Can you give me link to IP2716 module ?

Thanks

[tobychui]

Hi,
There are a few types of board on the market, the one I am using was from a Chinese site where you can get it here
https://item.taobao.com/item.htm?spm=a1z09.2.0.0.3...

[x893]

Thanks !