Power Bank Manufacturing Process: How We Make It Done?

Table of Contents

Ready to know about the making process of power banks?


This post contains our regular manufacturing process for power banks, including the standard quality control steps. 

Let’s jump right in.

IQC (Incoming Quality Control)

The process begins with our IQC department. After receiving the components, our IQC members will check whether everything is okay as below. 

1.1 100% appearance inspection of all raw materials, including housing, PCB boards (charging ports, LED light power, charging indicators/LCD screen), cells and cables.

1.2 Randomly select PCB samples. And test the functions like internal impedance by the PCB test system. 

1.3 Randomly select cell samples. And explore the real capacity by the capacity grading system.  

1.4 Randomly select cable samples. And check them if they work.

Generally, we will select 300 out of 3000 to 10000 PCBs/cells/cables. If over 3 units are defective, we will return the batch to the supplier. (AQL standard like Xiaomi used)

After that, we will store all the components in the temperature and humidity controlled area if needed.

Semi-finished Procedure

Now we are going to the assembling process.

Here are the steps we do.

2.1 Tinning pads on the inspected PCB boards. Then solder the wires on PCBs so that they can be attached to batteries. 


2.2 Tinning contacts on the lithium polymer cell. 

2.3 To prevent short circuits, we tape on contacts of the Li-Poly cell.


2.4 Stick the spongy material on the cell to stop it from flapping inside the case. (Only do if needed, not the necessary step)

2.5 Tape several li-on cells together. (Only do if required for high capacity, not the essential step)

2.6 Connect the cells and PCBs by soldering. 


2.7 Test the 2.6 unit function for charging and discharging to determine if they are okay to go. (100% checking)


2.8 Screw PCB into the underside housing to add security and stability.


2.9 Place the battery in the right place of the underside housing.

Place Battery

Aging Testing

Next up, we will move the semi-finished products to the burn-in rooms. 

Aging Testing 1

Some factories will skip the aging testing process so it can save time and cost.

However, it will cause many issues like unstable function if you prefer to “save things.”

Generally, we will do one cycle of charging and discharging (charge to 100% then release to 0%). And check all the things included voltages and currents are right to go. Then charge them to 70%-80% or in step with the customer’s requirement.

After that, the semi-finished products are back to the assembly line again. 

Aging Testing

FQC (Final Quality Control) & Packaging

So now, we need the following steps to make power banks ready.

4.1 Seal the final bottom piece of housing with hot glue. It can secure the bottom part.

4.2 Place the top casing with two double-sided tapes to ensure it is properly fixed on the bottom piece.

4.3 Press two halves of the housing by press machine. (30 seconds to ensure a secure fit)


4.4 Check charging and discharging function again to see any connection breakage or any defect.

4.5 Clean the dust particles on the power banks.

Clean The Dust

Then the power banks are passed on to the next stage – Packaging.

Typically, we will do 4 steps.

1. Put the cable and manual into the inner box.

2.Put the power bank into the inner box.

3.Place the inner box into the outer box.

4.Weight the packaged power bank to see if there is any mismatch. 

Production Line


So that’s it for our process to make the power banks.

Now I’d like to hear from you.

What are tips from today’s post useful for you?

Or maybe you want to have something better to add.

Either way, let us know by leaving a comment below.

Hi, I’m Ryan Gao, a father of 2 kids, also the content manager of MoruiPower.com. I’ve been working on consumer electronics for 8 years now. On this site, I like to share with you the knowledge related to power banks, wireless headphones, and portable power stations from a Chinese supplier’s perspective.

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