Hi there, as you might know during an older video of mine I explained why USB Type C is
awesome and just recently I released a video about how to make your own DIY USB Type-C
Power Delivery trigger board and spoiler warning; it was certainly not a simple programming
task.
That is why I was a bit scared about the next USB Type-C subject I wanted to tackle which
is about creating a DIY USB Type-C PD powerbank.
The reasons are comprehensible I think; For a pure DIY solution I would not only have
to program the PD protocol negotiations so that the powerbank can acts as a source to
supply power and as a sink to charge up its internal li-ion battery pack but obviously
I would also have to manage its battery pack by charging it up correctly and adding all
kinds of safety features.
So I said to myself why do I make everything always so complicated and that is why in this
video I will keep it simple and show you my journey of finding the perfect powerbank IC
for this task for which coincidentally a ready to use PCB already exists.
Then I will test this PCB extensively and finally use it in combination with some Li-Ion
cells I had lying around and a custom 3D printed enclosure in order to create a simple, yet
super useful USB Type-C PD Powerbank.
Let’s get started!
This video is sponsored by JLCPCB, who provide excellent quality PCBs for a very low price.
I have been using their service for years and can surely recommend it.
So why not upload your Gerber files today in order to test out their service.
Like pretty much always when it comes to finding a special IC, I visited LCSC, who offer thousands
of them.
There I searched in the PMIC Battery Management section where I got 930 results and thus it
took me a couple of hours to find an IC was happy with.
But eventually I found the IP5328P which is according to its English datasheet a Fully-Integrated
Bi-directional PD3.0 and Fast Charge Power Bank SOC.
Sounds complicated, but in a nutshell that means it got Quick Charge functionality, supports
USB Power Delivery with 5V and 9V as an Input and 5V,9V and most importantly 12V as an output
with up to 18W of power which is most of the time enough for my portable projects.
It also comes with all the battery protection features you need for Li-Ion batteries and
as a bonus it can even drive LEDs to show the remaining capacity of the battery pack.
Simply put this was the IC I was looking for.
But while going through the 28 pages of the datasheet I started to realize that creating
a PCB design for this IC might get a bit complicated.
So just for fun I searched for this IC on Aliexpress and quickly found a PCB based around
this IC which not only looked promising according to its picture and the functional description
text but the price was also quite tempting.
That is why I could not resist and ordered one which after unpacking, made a positive
impression concerning its PCB and solder quality.
The only question was whether this PCB could fulfill all the features I was hoping for?
And by that I mean how fast can it charge up its battery pack, how much current can
it supply at which voltage level with the Power Delivery, how efficient is the circuit
while doing all of that and does the charging of the battery pack with all of its protection
features work?
So let’s start off with the charging test for which I got this USB Type C PD charger
and this common phone charger that supports Quick Charge.
Before hooking the chargers up though I grabbed myself an old Li-Ion cell I had lying around
and connected its two terminals to my Power Meter and the B+ and B- Terminal of the PCB.
Then I started the charging test by shoving a USB Tester into the phone charger, plugging
all of that into an outlet and connecting the charger to the board with a micro USB
cable.
As you can see quick charge seems to work fine since the phone charger provides 9.2V
with a current of around 1.8 A which is even above the chargers limit.
That equals an input power of around 16.5W, while the battery only gets charged up with
a power of around 13.7W which means that the efficiency is around 83% and thus certainly
acceptable.
And if you are wondering if we use a USB Type C cable for the phone charger then the voltage
and current values pretty much stay the same.
Now if we replace the phone charger with the USB type C PD charger and hook up all the
cables then we can find out that here the voltage is also 9.2V but with a slightly smaller
current value of 1.7A which was not the chargers limit.
So I guess an input power of around 16W is the maximum.
That is not too bad considering that my small commercial USB Type C powerbank only features
a slightly higher input power limit.
Now since I later want to add a battery pack with a capacity of 74Wh, it means that the
overall charging time would take around 4.6 hours in my case.
And considering that the circuit draws a standby current of only 54uA, the battery pack will
never run empty.
But anyway while charging up the battery I not only realized that the LED indicator worked
just fine and the charging method of the li-ion battery was suitable but also that the overcharge
cut off voltage was around 4.23V and thus still acceptable.
So all in all I was pretty happy with the charging/input features of the board and thus
it was time for the output tests.
I started by hooking up an USB Type C PD trigger board to the circuit which as you can see
can cycle between 5V, 9V and 12V without a problem.
That is why next I hooked up a constant load to the output in order to test whether the
circuit can truly output the current that it promised in it description text.
And to my surprise the circuit was truly capable of outputting the promised 3.1A at 5V, 2A
at 9V and 1.5A at 12V.
And while doing this test I not only measured the output power but also the power the battery
had to provide which later let me create this beautiful graph.
As you can the efficiency of the converter pretty much always stayed at around 80% and
only one time dipped down to around 75% which is pretty decent.
Last but not least for the discharge test I let the circuit charge up my Nintendo switch
and while doing so I monitored the voltage of the Li-Ion battery.
As you can see at a voltage of around 2.9V, the circuit cuts the power output which was
a suitable cut off voltage value.
So all in all I can say that I was also happy with the discharge/output test and thus it
was time to turn this circuit into a proper powerbank.
For that I firstly got myself these 6 NCR18650B Li-Ion cells which I salvaged from an old
battery pack.
For this powerbank we need to connect them all in parallel to basically form one big
battery but let me tell you that this is only possible because they were previously used
together and their voltage values only differ very slightly with a value of around 0.03V
from one another.
If you would stick together random cells you got lying around then this could end very
badly, you have been warned.
But nevertheless I positioned all my cells into 18650 plastic spacers before I connected
them with one another through the help of some nickel strips and my KWeld spot welder.
As soon as that was done all I had to do was to solder a wire to the plus and minus terminal
and connect them to the PCB according to this rather easy to follow wiring diagram.
And that is basically how you can make a super simple USB Type C PD Powerbank but of course
a proper enclosure was still missing.
So I measured the dimensions of the PCB and the battery pack and within a couple of hours
created this enclosure for it all in fusion 360.
After then 3D printing this housing with my 3D printer and some awesome looking PLA filament,
I hot glued the battery pack inside the enclosure, secured the PCB with screws, once again soldered
the battery wires to the PCB and finally closed everything up and used some more screws and
nuts to keep everything together And just like that you can easily build your
own USB Type C PD Powerbank which according to its specifications sits right between my
two other USB Type C PD Powerbanks.
I hope you enjoyed this video, if so don’t forget to like, share, subscribe and hit the
notification bell.
Stay creative and I will see you next time.