Introduction: Adding an External Power Supply to a Cheap USB Hub

Picture of Adding an External Power Supply to a Cheap USB Hub

One day I found myself in the need for a USB hub with an external power supply but when I went to a shop I verified they can be quite more expensive than the ones that don’t ha\ve external power supply. No big deal, “I’ll just by a cheap one and add the external power supply”, I thought. And that’s what I did! After all I just had to add a wire on VCC, another on GND and cut the VDD wire of the USB cable that connects to the computer.. So, I went to a shop and bought the cheaper USB2.0 USB hub that I found and took it home for some small hacking.
This instructables has only 7 steps:

  1. Inspect the USB hub for signs of upgrades
  2. Open the enclosure
  3. Locate the GND and VCC traces and solder a wire to each one of them.
  4. Solder a connector to the wires.
  5. Cut the VCC (red) wire of the USB cable that connects the hub to the computer.
  6. If necessary, modify the enclosure to make the connector for the power supply accessible.
  7. Close the enclosure

For this instructable you will need the following tools:

You will also need the following skills:

  • Basic circuit analysis skills (continuity testing, voltage measuring)

For better quality pictures check out

Step 1: Inspect the USB Hub, Open It, and Inspect It Again

Picture of Inspect the USB Hub, Open It, and Inspect It Again

A good inspection of the device may make everything a lot easier than expected. The USB hub that I used had the shape of a 4-pointed star and in one of the corners there was the USB cable. However, I noticed that on another corner of the enclosure there was just a small hole. “Weird! Why is this hole here?”, I thought. I opened the case and right next to that unexpected hole, there were three holes in the PCB without any component inserted on them. I started to guess that those holes in the PCB and the hole in the enclosure were to solder the connector for an external power supply. I used my multimeters’ sound probe to verify if my suspicion was correct and fortunately it was! Two of the holes were on a GND trace and the another one was on the VCC trace.
Probably there are two versions of the same USB hub being the only difference the presence or the absence of the external power supply connector. I guess it’s a lot cheaper for companies to manufacture a big amount of a single printed circuit board than to order smaller amounts of two different boards

If your USB hub doesn't already have holes for the connector, look for the USB cable and find the VCC(red wire) and GND(black wire) tracks. Solder a wire to each one of them. If it is a single sided board you can even drill some holes in the tracks to solder the wires or a connector.

Step 2: Get a Connector and Solder It in Place

Picture of Get a Connector and Solder It in Place

Luckily I had a connector that I had scavenged from some other device. I soldered the connector. In the case of your hub, if you soldered two wires, just solder the connector to the wires. Make sure you solder the VCC to the right pin of the connector.

Step 3: Cut the VCC Wire of the USB Cable

Picture of Cut the VCC Wire of the USB Cable

This is the last step of the hacking. Just look for the USB cable that connects the hub to the computer and cut the red wire (VCC), so that the computer will not be able to provide current to the USB hub. The USB hub will not be able to provide current to the USB port either.

Step 4: Test the Hub

Picture of Test the Hub

All the hacking has been done by now. Get a regulated 5V power supply and plug it in the connector. If you hub has any "power on led"it should be emitting some light. That's a good sign. If everything is ok, plug the USB cable into the computer and check if the hub is recognized. In linux you can open a terminal and type "lsusb" to see if the hub recognized. If it is recognized, plu some device in it and test if it works.

Step 5: Put It in the Enclosure and You're Done!

Picture of Put It in the Enclosure and You're Done!

If everything worked you can put the hub in its enclosure and you're done. Depending on the router that you have you may have to modify the enclosure to make the connector accessible. Hope it's useful for you :)

For a longer story about it and better quality pics check


Poppo_Popporation (author)2017-11-19

Hi, I try to do this instructables: the current runs at 100%, but the hub is no longer recognized by the pc. Can anyone explain to me why?

RajaCellular (author)2017-11-03

A unit load is defined as 100 mA in USB 2.0, and 150 mA in USB 3.0. A device may draw a maximum of 5 unit loads (500 mA) from a port in USB 2.0; 6 (900 mA) in USB 3.0. (source:

So, if you have more hubs, you'll need more current (ampere).
No need to increase the voltage, just the current.
Get these extra current from another power source, dont take it from your computer.

Good luck and be careful for playing with electrical current.

Atle SeppolaG (author)2017-10-29

I'm planning on adding an external power supply to one of these units, but have to say I'm a bit short on how much current I can push into it. The hub has 4 ports, would it go crazy if I give it 5v 10A? Not an expert on this, but in my head that would be just fine since the connected units take what they need and nothing more? And will that current be divided by four all the time (2.5A on each port?), even when there's only one unit connected to the hub? Would be great with some extra information regarding this issue in an article like this. :-)

Or do I have to think like usb 3 = 900mAh x 4 = 3.6A, or is that only when power is coming through the usb-cable and not from an external source?

msaleiro (author)Atle SeppolaG2017-10-30

Hello. If the PCB traces can handle the 10A that will be no problem. The connected units will only take what they need and it will not be divided by 4 all the time (one unit can take 5A and other device 3A, other 2A and other 0A). The USB 3 power is the power from the USB ports on the computer. If you plug an external power source you can get much more, as long as the PCB traces and USB cables can handle the larger amount of current.

LizY5 (author)2017-09-01

i want to use a twelve foot telephone cable with this mod, cut off both ends of telephone cable solder a usb for pc on one side on the other end use your mod, i only will use data lines from pc usb port. usb cables are too bulky for my pc cams that are 12 foot away.

LizY5 (author)LizY52017-09-01

any tips are apreciated

DMoRiaM made it! (author)2017-07-15

I got the same hub as yours and did the same. Now I will disassemble it and change the ports with screwable terminals and adapt it in a small project of mine! Thanks for the idea!

T FawazelulR (author)2017-01-30

hat kind of power adapter can i use? can i use a power adapter from a
rc car charger? cuz it seems like the connector and the power adaptor
cord is plugabble.. but i dont brave enough to test it LOL xD

msaleiro (author)T FawazelulR2017-01-31

Hi. You need a power adapter that outputs 5V. If you get one with 5V 1A or 2A it will do.

mbjrgk (author)2016-07-23


Excellent and most innovative idea, just stumbled upon it while searching (to buy) a powered USB Hub . Thanks to you , saved me almost 500 Rupees (Indian)approx$8.

Very well explained and illustrated and also followed up with informative replies ... Do keep it up and also Big Thanks to INSTRUCTABLES ...

msaleiro (author)mbjrgk2016-07-23

Hello mbjrgk,

thank you very much for your kind words. I'm glad it was useful for you :)

TimS226 (author)2016-06-27

The software solution may help you to share any devices, you can share even USB Hub over Network.

Really helpful solution to manage all USB devices.

raskoe (author)2016-05-22

If you want, and know someting of electronic you can put a diode on the red wire

Then your hup can switch bitween the 2 *suplies*

You need a diode with a low voltage drop and one that can handel the curent.

MahamadA2 (author)2016-04-12

I have a few questions here..

Can I use one of the USB ports available on the hub to power that hub?

What I mean is this :

1- I'll get a male to male USB cable.

2- I'll plug one end of the USB cable into a USB charger (2.0A, 5V).

3- I'll plug the other end of the USB cable into one of the ports available on the USB hub.

4- I'll cut the hub's VCC red wire as you mentioned above.


1- Will this work?

2- Will the hub then provide the correct power to the rest of the ports (500mA,5V for each of the 3 empty ports)? "assuming it is a 4 ports hub of course", or doing so will need extra steps and procedures?

3- Assuming all ports working at full capacity, if each port requires a 500mA, 5V, so for a 4 port USB hub, wouldn't that require at least a 2.0A, 5V adapter? or will any adapter work? (say a 500mA, 5V), how this works actually?

4-Will it be safe to plug my stuff then? USB HDD, external drives (DVD, HDD ..etc), flash drives, card readers ..etc, I mean will there be any extra power delivered to them somehow because of the charger or the cable specifications? do I need to be cautious of same?

5- Can I use some or all of ports this way to charge multiple devices while using the hub for data transfer? (mobiles, tablets, power-banks, speakers ...etc)

6- Will the hub provide only 500mA, 5V for the ports used for charging? or will it provide more for the charging processes?

7- If it will provide more for the charging processes, will that need a more powerful charger? or will my 2.0A, 5V work just fine?

8- And finally... is there a USB hub that already does all of what I have been asking about? (I mean powered by one of its USB port (or just a separet USB port), and can be used for data transfere and charging at the same time, with adjusting the specific power each port recieves? like 500mA, 5V for normal operations ports , and 1A, 1.5A, 2.0A 5V for charging ports)

Sorry for the too many questions, and this was very useful indeed! thank you!

msaleiro (author)MahamadA22016-04-13

Hi! If the all the USB ports share the same VCC and GND lines, yes, you can do that. Just don't forget to cut the VCC (red) wire that goes into the computer. The current available for all the ports will be the maximum current of the power adapter. If you have a 5V/2A power adapter the ports will have to share the 2A. If you only plug one device to one port and it needs 2A, it will be ok. If you put two devices that need 2A, it will not work. There will be no physical limit to the current that can go into any port, except the current limit of the adapter. Using a simple analogy: if you have 1 cup full of water (power adapter) and 4 empty cups (USB ports) you can either put all the water into one cup or split it among the cups as you wish. Each device has it's own current specification and it will try to get that current from the power adapter, if the power adapter can provide it. You'll never have to adjust any current for any device since they will "ask" (not really the right word) for the current they need to the power supply. I didn't answer the questions one by one because they are somewhat repeated. However, I think I have explained everything you need to know. If not, just eep asking :)

MahamadA2 (author)msaleiro2016-04-14

So the more powerful the adapter, the more current available to ports, and yes everything is now crystal clear, thank you, plus I found some valuable information in previous comments and other websites (I should've done some reading first), and the questions are.. well, not repeated.. but indeed dependent on each other.

Thanks alot for the quick reply, and I've done it already and testing it now on various devices, I just want to measure the voltage and the current on each port during operation, will that affect the function of the devices? like causing data loss or corruption if there is a data transfer going on

I'll be using something like this :

msaleiro (author)MahamadA22016-04-14

Yes, you can measure during use without any problems. However, be careful. Voltage is measured in parallel, which means you can simply put the test probes in any point of the circuit without any problem. On the other hand, current is measured in series, which means that you have to break the connection that you want to measure and use the two probes in the place that you break the connection so that the current flows through the multimeter. Otherwise you'll probably damage your multimeter or at least the fuse inside it

MahamadA2 (author)msaleiro2016-04-14

I'll be very careful of course :)
and the tests went OK, I only experienced issues with a usb wifi adapter, the connection was poor and kept dropping, I changed the usb cable and the dropping gone, but the connection still poor, (the usb wifi adapter worked fine on that hub before), I think there must be a noise somewhere, do you have any idea where it comes from?, or maybe there is another reason in your opinion.

IvoP5 made it! (author)2016-01-28

i made this and it works a charm Amazin instuctions as a test i went to see how many phones i can charge and i could charge a phone on all 4 ports obviously really slowly but still possible :D

msaleiro (author)IvoP52016-01-28

Very nice to see you made it even with a different hub! Congrats! :)

chaitanyagore (author)2015-11-13

we have to justwehavetojust remove red wire among the wires 4 and provide externalexternal power of 5v by means of any adapter

NeuroPulse (author)2015-08-24


Does more than one USB device work at a time on that hub? I ask because it does not have any chips on it.

I found this instructable while trying to find out if USB splitters require circuitry.

Do you know if USB hubs require controller chips?


cosmicaug (author)NeuroPulse2015-08-25

I see an epoxy blob (close to the middle toward the side away from the USB and data connectors side —see that is probably covering a controller chip that arbitrates the bus and power.

In any case, I took apart a hub of my own and it looks like the one above in that there are no direct connections between the signal pins which instead go to a chip.

At the very least, a USB 2.0 (or above) hub has to be able to translate to so that you can use devices following different standards (1.1) so a controller would be needed for that. Even for USB 1.1 the hub would have to be able to serve as a repeater. You clearly need a controller.

msaleiro (author)cosmicaug2015-08-25

Thanks for answering NeuroPulse's question! Great answer! :)

SuhailA1 (author)2015-08-04

Could u please tell me the specifications of the adapter? how much output current is needed to power a 4 port hub?

msaleiro (author)SuhailA12015-08-05

Hi! That depends on the devices that you plan on connecting to the hub. If you're going to plug in a hard drive it may take more current than 2 usb mouses, for example

SuperT2 (author)2015-05-31

Do i just have to replace the red and black wires?

NickJ2 made it! (author)2015-05-15

Thanks very much for the instructable. Managed to convert a keyboard with two usb ports on it into a powered hub, now I can use both a proper keyboard and wireless mouse with my Microsoft surface.

SuperT2 (author)NickJ22015-05-31

How do you do it? Ive got the same keyboard. Did you use this method?

msaleiro (author)NickJ22015-05-15

Hi! I'm glad you could learn enough things from my instructable to make your own hack into another device :)

NickJ2 (author)msaleiro2015-05-15

Once I realized it was the current that was the issue with uncovered hubs not the voltage it all made sense, the surface only provides enough current to power one device. Now that mouse and keyboard work I'm gonna try plugging my ext hd to the extra port and see what happens

SuperT2 (author)2015-05-31

My keyboard has 2 usb's behind it. Can i use this method to give iy external power?

rcrusem6 (author)2015-05-06

Hello sir. I don't see a power ports on my hub. Will this work if I desolder the red and black wire from the USB cable connected to PC and replace it with red and black from the power supply?

msaleiro (author)rcrusem62015-05-06

Hi! Just desolder the red one from the cable that goes to the PC and keep the black one soldered. Connect the red one to the power supply. Then solder another black wire to the existing black wire and connect it to the power supply. After that, you're done :) Good luck!

nyacumo (author)2015-04-21

Hi. Thanks for this tutorial. I would like to conect the male usb cable to an otg adapter and then to my samsung s4.Will this setup charge or keep charge my phone? (Im confuse whether i jave to cut or not the red cable in this case) yhanks in advance from argentina.

msaleiro (author)nyacumo2015-04-21

I'm not sure if I understood what you want to do. You want to use the hub to connect multiple devices to your phone?

nyacumo (author)msaleiro2015-04-22

Yes i have a samsung s4. I would like to connect several accesories to my cellphone in this order s4-> otg-> usb hub+ ext power. The idea is to connect everything and charge the phone at the same time.

msaleiro (author)nyacumo2015-04-22

Ok, so in your case you shouldn't cut the red wire. However, be aware that some of the other USB ports (or an external connector, if your hub has one) will have to provide power to all the devices. Your phone will not be able to handle all of them. Also, I am not aware of how the power is managed in the USB OTG ports and although I think nothing bad will happen, I take no responsbility if it does :P

nyacumo (author)msaleiro2015-04-23

Thank you very much for your kind reply

nyacumo (author)msaleiro2015-04-22

Yes i have a samsung s4. I would like to connect several accesories to my cellphone in this order s4-> otg-> usb hub+ ext power. The idea is to connect everything and charge the phone at the same time.

nyacumo (author)nyacumo2015-04-22

Mouse keyboard and ext hdd basically

GianniM (author)2015-03-18

Do you think that if a phone doesn't have OTG feature it's just that it doesn't power the USB devices? I mean, if I add a 5V external power source to a hub, will my cell phone detect the pendrives/memory sticks?

msaleiro (author)GianniM2015-03-23

It will depend on the phone and its specifications. If the phone firmware does not include drivers to handle USB devices, they will not be recognized.

nyacumo (author)msaleiro2015-04-21

Hi. Thanks for this tutorial. I would like to conect the male usb cable to an otg adapter and then to my samsung s4.Will this setup charge or keep charge my phone? (Im confuse whether i jave to cut or not the red cable in this case) yhanks in advance from argentina.

GianniM (author)2015-03-18

Question: if instead of adding a connector to the hub, I plug a USB charger into one of the ports, will it work? Of course, cutting the red, 5V wire inside the hub before.

msaleiro (author)GianniM2015-03-23

Yes, it should work fine :)

GianniM (author)2015-03-17

But if you plug the hub to a PC, and you add an external 5V source, wouldn't that collide with the PC's own 5V that will too be present in the hub?

msaleiro (author)GianniM2015-03-17

Yes, that's why you need to cut the red wire in step 3 :)

jack.mogren (author)2015-03-17

Thanks for this Instructable. I've had a problem with suppling ample power to a camera device via a 10 meter active repeater USB cable and this is the answer. As I found out, an active repeater cable only provides for a good USB data source between devices, not adequate amperage.

kwayakashi (author)2015-02-03

Great instructable, msaleiro - thanks so much for posting this. I wonder if I can use any 5V regulated power supply regardless of the Ampere/Wattage? Can I use a 5V adapter that I got from other devices?

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