Introduction: 3D Printed 12000mAh Power Bank

About: I'm a senior software developer who loves working on projects involving software, electronics, woodworking, 3D printing and all things DIY.

One can never have enough power banks!

I had a few LG HG2 18650 3000mAh cells that I wasn't using, so why not 3D print a case and make a beast of a power bank?! :D

Please Note:
This is NOT my design. All credit goes to
Kim3DIY for his amazing work!
Here is his Instructable:

Step 1: Tools Required

Here are the tools you'll need:

  • 3D Printer - I used my Anet A8
  • Soldering iron
  • Solder wire (flux core preferable)
  • Electrical wire
  • Glue Gun
  • Wire cutters
  • Screw Driver

Step 2: Components

Step 3: Print Parts

I used the following Thingiverse item:

Printed on the Anet A8 with the following settings:

  • Layer Height: 0.2mm
  • Filament: CCTree PLA 1.75mm
  • Infill: 10% - you should go higher - 20-30%
  • Print Temperature: 190/60
  • Print Speed: 60mm/s
  • Travel Speed: 120mm/s

Step 4: Solder Wires to Battery Holder

I used red for positive and black for negative.

Step 5: Solder Power Bank Module to Holder

Make sure you got the polarity correct.

  • The red wire should go to the BAT+ on the board
  • The black wire should go to the BAT- on the board

Step 6: Insert Batteries and Test the Module

Before you hot glue the battery holder and module into the case, insert the batteries to test if everything is working correctly.

Make sure you get the polarity correct!

You don't want to connect this cells in the wrong polarity - it will damage(burn) the module!

The cells are connected in parallel - all the positives will connect to the +'ve rail and all the negatives will connect to the -'ve rail.

Since they are in parallel and each cell has a rated capacity of 3000mAh, this will result in a total capacity of 12 000mAh!

Step 7: Insert Components Into Case

I had to sand down the reset button part a little and drill the hole in which it goes.

Other than that, everything should fit snug :)

I then used hot glue to secure the components and LCD

Step 8: Screw Lid and Print Labels

I used 4 x M3 screws to secure the lid on the case

I then used my label maker and printed some labels :P

Step 9: Done!

There you have it!

All you have to do now is wait patiently as it charges up.


It takes a while since the charging board only allows ~300mA of current to charge the cells. Unfortunately, this means that it'll take ~40 hours of charging from 0-100%.


The power bank has two ports, 1A and 2.1A. When you connect something the LCD will indicate which port you are using.
The module has a button which performs the following:

  • Long Press = Turn on/off the power bank
  • Quick Double Press = Turn on/off LED torch