If you're interested in DIY modifying power banks, you might want to check out this article.

If you have a power bank like the one below and are thinking about modifying it, then follow along and let's DIY it together.

The power bank in this article uses two 18650 cells, with both input and output at 1A.

This kind of output efficiency is pretty low. The inductor and diode are shown in the picture below.

If you want to push it to 2A, you'll need to get Injoinic's IP5306 chip—it's highly integrated.

The circuit is also pretty simple.

Next, you can design the board and get it manufactured.

Then you can use a craft knife to make the cuts.

You'll also need a file to shape it, then put it inside the power bank to check the fit. It just needs to be the right size.

Here, the inductor is actually wrong; you should use a 10mm inductor, not the 7mm package. If you've gotten this far, you can keep going.

You can prepare a 7mm plug-in 1R2 inductor for the modification. Of course, if you have a 10mm inductor, even better.

You'll need to take the chip out.

You can remove a turn, which will give you exactly 1uH.

Then you need to put it back in and apply some glue to secure it.

Next, prepare the following components.

Then solder them together.

After testing, it works—no load voltage is around 5.2V.

Then you need to clean off the flux and put it back in the case.

Check the input—it shows 1.8A, which is not bad.

But the output is only 1.5A.

The output voltage is 4.6V, which might be caused by that inductor.

If you've gotten this far, next time you make a prototype, you can switch to a 10mm inductor.

The end.