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I finally finished my DIY 100W Power Bank project and I'm excited to share it with you. As a electronics enthusiast, I've always been fascinated by power banks and their ability to charge devices on the go. In this episode, I'll take you through the entire process of designing, building, and testing my own 100W power bank.

First things first, I needed to set up my PCB and resistor configuration. This was a crucial step, as it would determine the output voltage and current of my power bank. I used a 27kohm resistor to set the current to 5A, which is suitable for my pack. With that out of the way, all the input and output theory was finally done, and I moved on to soldering a + and – wire to the board and connect it to my lab bench power supply set to the battery voltage.

At first, the board was not in the mood to deliver any output voltage, and I had to hook up a power source so that the yet not existing battery pack gets initially charged and thus recognized. With that out of the way, I was able to activate all the different voltage levels we talked about, and next I lowered the input voltage for the board to see how the battery level monitor LEDs would react. But they apparently didn't care at all.

I found out that the IC utilizes a fuel gauge monitor meaning it only determines the initial battery charge through the startup voltage and then simply measures how much power is going in and out to light up more or less battery level LEDs and of course, all that is in accordance with the set capacity of the battery pack. I properly tested this later, and this feature seems to work just fine.

Next, I did the 100W power test with my constant load to see if that actually works, and as it turns out, the output voltage does drop a bit too much while drawing 5A. At 4.6A however, the voltage is still acceptable, and I guess 90W of power is still pretty good for such a board that doesn't even get hot while pushing that much power, meaning I could touch all the components without getting burnt.

While I was already doing current tests, I tested out a bunch of different current flows at different voltage levels while writing down the input and output power. And as it turns out, the max current at the different voltage levels was always possible, according to this efficiency graph you can see that the board is also quite efficient.

Last but not least, I lowered the simulated battery pack voltage to see if the PCB would cut off its output power to prevent an overdischarge which it did at 11.5V so 2.9V per Cell which fits just fine.

With all the output testing done, it was finally time to create the actual battery pack for which I only needed an additional spot welder and a couple of smaller nickel strips. I used them to firstly create the parallel connections and after aligning all the cells correctly afterwards, I used them once again to create the series connections. Only cover this topic briefly here because I created such battery packs a few times in past video so definitely check them out if you are looking for more information.

And with the bare battery pack complete and outputting all the correct voltages, all that was missing was adding a BMS like this one right here which adds over-current, over-voltage and under-voltage protection and also balances the individual cells so that none gets overcharged. All I had to do was mount it to the battery pack, solder the wires to the appropriate cells, plug in the connector and add power wires to the pack and BMS.

And after then connecting those power wires to the PCB, my DIY Power Bank was more or less complete. First of course, I tested the charging capabilities, and it seems to charge very fast by pumping 4.5A into the batteries. Of course, let the whole pack also charge up completely in order to confirm that the PCB truly cuts off the charging at the correct voltage.

For the last tests, I once again tried some output loads which all worked fine, using the power bank to charge up more traditional electronics was also no problem. So all in all this DIY almost 100W Power Bank is not half bad and the only real criticism I got for it is that it only comes with one input and output port and that it misses such a useful display, the Buy version comes with.

But aside from that, it also got tons of good things going for it which I summarized in this chart here. And the winner for me in this episode are actually both DIY and Buy because I think the Buy version here really offers a good cost performance ratio.

Now to finish off my DIY version though I of course also designed a fitting enclosure for it which I then 3D printed. With all the electronics placed and screwed inside there snugly and closing it all up, my project came to an end, and I hope you enjoyed it and maybe now know how to build your own 100W power bank.

Please let me know if this is what you were looking for!

WEBVTTKind: captionsLanguage: enSo this thing may look like an ordinary powerbank with all of its USB inputs and outputs;but if we take a closer look at the labelon the front it is clear that this is somethingspecial.Because yes; this power bank can output 100Wof power which is enough to fully illuminatethis super bright 100W High Power LED.Outputting so much power with such a smallbattery pack is pretty crazy when you thinkabout it because in theory you could partlypower a PlayStation 5 with it or even my workhorse computer.Even laptops can be charged and solely poweredby such power banks.And this is of course all possible becauseof the USB C connector and all of its standardizedprotocols like PD aka power delivery.With it you can can get 20V from the powerbank which multiplied by the maximum currentof 5A equals our 100W.So far this all sounds fantastic but a smallproblem arises when you look at the capacityof this power bank which is 74Wh.If you divide that capacity by 100W then thispower bank is empty within around 45 minuteswhich is not very long and it could only chargeup a modern laptop battery around 1.something times.So what we need is a bigger battery and luckilyI recently found this purple PCB on Aliexpresswhich according to its description could helpus to create a DIY Power Bank with hopefullymore capacity and still a 100W Output.And that of course brings us to the age oldquestion whether we should DIY or Buy sucha 100W power bank and at the end of this videowe will hopefully have a clear answer.Let's get started!This video is sponsored by Onshape which isthe CAD Software I used for this project todesign the enclosure for my DIY Power Bank.And the best news first this CAD softwareis free to use for anyone, and has plans specificallydesigned for businesses as well - and sinceit runs in pretty much any modern web browserand works like google drive, you can use thissoftware on almost all devices, no joke.Of course it also comes with all the designfeatures you would expect from such a professionalsoftware and after just a couple of minutesof using it I was comfortable with it andthus created my powerbank design within anhour.So If you want to give it a try go to Onshape.Pro/GreatScottor click the link in the video description.Now before starting anything with the PCBI firstly of course had a closer look at itand I have to say that the quality is prettygood.Its main IC is the IP2368 which accordingto what I can decipher from its Chinese datasheetas well as the product description of thePCB, can not only do all the USB C communicationbut it also manages the power electronics.In our case those are mainly 4 N-Channel MOSFETsand one big inductor which together form anH-Bridge Synchronous Buck Boost Converter.Sounds complicated but in a nutshell sucha converter takes the battery voltage andeither steps it up or down to reach the 5V,9V, 12V, 15V and 20V which USB C is knownfor.For each voltage level the converter alsocomes with a maximum current rating and hereI am honestly most curious about the 20V 5Aone.So what the PCB can output is clear but whatabout the input side with the batteries?Well, according to the product descriptionyou can set all the important battery packparameters by using different resistor valuesfor resistors that can be easily solderedto the PCB.Those parameters include the battery chemistry,how many battery cells you want to use inseries, what capacity your pack comes withand what charging end voltage it requires.And if we for example calculate with the maximumratings then we could use a battery pack with25Ah and a nominal voltage of 22.2V whichis 555Wh in total and that is 7.5 times morecapacity than the buy version, not bad.In my practical case though I ordered myselfthose 18650 Lithium Ion cells from LG whichcome with a capacity of 3.2Ah and can output10A each.I will be putting 2 of them in parallel todouble their output and capacity to 20A and6.4Ah and 4 of those pairs in series in orderto increase the voltage to 14.8V.This way the final pack should be able tooutput 296W which is more than enough andit will come with a capacity of 95Wh whichis a step up from the buy version.And best of all the standard resistor valuesof the PCB pretty much represent all the parametersof my battery pack.The only thing missing was the charging currentwhich for my pack could be at max around 6.2A.Only problem was that the product descriptiondidn't mention the charging current at alland I had to investigate the Chinese datasheetwith google translate in order to find outthat the board was in fact in the constantcurrent charging mode and the charging currentis set by this resistor that is 27kohm andthus sets the current to 5A which is suitablefor my pack.And with that out of the way all the inputand output theory was finally done and I movedon to soldering a + and – wire to the boardand connect it to my lab bench power supplyset to the battery voltage to do some initialtests.And at first the board was not in the moodto deliver any output voltage and to solvethat I firstly had to hook up a power sourceso that the yet not existing battery packgets initially charged and thus recognized.With that out of the way I was able to activateall the different voltage levels we talkedabout and next I lowered the input voltagefor the board to see how the battery levelmonitor LEDs would react but they apparentlydidn't care at all.What I found out is that the IC utilizes afuel gauge monitor meaning it only determinesthe initial battery charge through the startup voltage and then simply measures how muchpower is going in and out to light up moreor less battery level LEDs and of course allof that is in accordance with the set capacityof the battery pack.I properly tested this later and this featureseems to work just fine.So next I did the 100W power test with myconstant load to see if that actually worksand as it turns out the output voltage doesdrop a bit too much while drawing 5A.At 4.6A however the voltage is still acceptableand I guess 90W of power is still pretty goodfor such a board that doesn't even get hotwhile pushing that much power meaning I couldtouch all the components without getting burntand we need no additional cooling.And while I was already doing current tests,I tested out a bunch a different current flowsat different voltage levels while writingdown the input and output power.And as it turns out the max current at thedifferent voltage levels was always possibleand according to this efficiency graph youcan see that the board is also quite efficient.So last but not least I lowered the simulatedbattery pack voltage to see if the PCB wouldcut off its output power to prevent an overdischarge which it did at 11.5V so 2.9V perCell which fits just fine.OK, with all the output testing done it wasfinally time to create the actual batterypack for which I only needed an additionalspot welder and a couple of smaller nickelstrips.I used them to firstly create the parallelconnections and after aligning all the cellscorrectly afterwards, I used them once againto create the series connections.I only cover this topic briefly here becauseI created such battery packs a few times inpast video so definitely check them out ifyou are looking for more information.And with the bare battery pack complete andoutputting all the correct voltages, all thatwas missing was adding a BMS like this oneright here which adds over-current, over-voltageand under-voltage protection and also balancesthe individual cells so that none gets overcharged.All I had to do was mount it to the batterypack, solder the wires to the appropriatecells, plug in the connector and add powerwires to the pack and BMS.And after then connecting those power wiresto the PCB, my DIY Power Bank was more orless complete.First of I of course tested the charging capabilitiesand it seems to charge very fast by pumping4.5A into the batteries.I of course let the whole pack also chargeup completely in order to confirm that thePCB truly cuts of the charging at the correctvoltage.And for the last tests I once again triedsome output loads which all worked fine andusing the powerbank to charge up more traditionalelectronics was also no problem.So all in all this DIY almost 100W Power Bankis not half bad and the only real criticismI got for it is that it only comes with oneinput and output port and that it is missingsuch a useful display the Buy version comeswith.But aside from that it also got tons of goodthings going for it which I summarized inthis chart here.And the winner for me in this episode areactually both DIY and Buy because I thinkthe Buy version here really offers a goodcost performance ratio.Now to finish off my DIY version though Iof course also designed a fitting enclosurefor it which I then 3D printed.And with all the electronics placed and screwedinside there snugly and closing it all upmy project came to and end and I hope youenjoyed it and maybe now know a bit more aboutsuch 100W Power banks.If so consider supporting me through Patreonto keep the show going.Don't forget to like, share, subscribe andhit the notification bell.Stay creative and I will see you next time.