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:

• Precision screwdriver set
• Side cutters
• Soldering iron
• Solder
• Digital multimeter

You will also need the following skills:

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

For better quality pictures check out http://www.thebitbangtheory.com/2012/06/adding-an-external-power-supply-to-a-cheap-usb-hub/

Step 1: 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

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

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

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!

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 http://www.thebitbangtheory.com/2012/06/adding-an-external-power-supply-to-a-cheap-usb-hub/

Comments

[jalvato]

my main objective is to modify some cables not the hub and only use light end perioherials like keybiard and mouse for gaming in android but as my battery consumption i am looking forward to this topic,

hey. lemme go straight to the point as of some research you were the one one doing this modification, so lemme specify my objectives:

1)the usb hub and the components inside are given in pic below plz review it and give suggestion to me as mentioned pints

2)so the thing i wanna do is charge my android phone as well as use the hub with the otg option.

3) my ideas on it are using 1 female to 2 male usb A cable ,

using this option because i dont want to damage the usb hub,
i will just connect the hub male cable to the female extension i had made
and the female port should be having power from a charger as there is 1 male usb a connector ill plug that in my 5v 2.4 A charger but only solder the power cables in the female connector.. the other male cable (soldered to the data cables of female port only,)should be connected in my android using otg, now the point arises how to charge my phone keeping in mind the is hub connected with otg,

NOTE: how i got the idea of charging my phoneas well as using the usb hub, as when i connected my phone to laptop or pc my phone charges as well as transfers ata so that way i got an idea,
a)as the male cable which is connected to the phone have have power wires not soldered should i attach another charger and get the desire output

b)or solder the usb A cable coming from phone soldered to the female part where the charger power is connected in that way if i dont use chrger i still will be able to use phone battery as the power source but the main objective is not to use the phone power but if power wentout then phone battery shiold be an exception.

4) plz provide another suggestions as of ur saying own opinion or different method on, charging my phone and using the usb hub but no modifications should be done in the hub,

[SvNtCfFf]

MAN, this mod is FREAKING NOT WORKING ! this does NOT respect USB spec, and if you do it (I did on a cheap hs8836a chip based hub), then plug that hub in a raspberry pi and it will NOT BOOT ! because the hub then does not answer to VBUS detection !

see : https://electronics.stackexchange.com/a/323551

[Poppo_Popporation]

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?

[ahsoni]

Same thing, after adding external power supply USB device / HUB is not recognised. I checked the connections using multi-meter and all wires are perfectly connected.

[diegosynth]

Same happened to me. I didn't damage anything, just removed VCC and soldered together ground cables to the original ground location. Phone charges fine, computer won't even notice anything. Maybe the cable I added is too thick compared to the original extra thin wires, but i'm sending several amps at 5V. Tried with 2 pc and 2 power supplies.

[msaleiro]

Maybe you damaged something in the process. Make sure the GND wire is connected and the D+ and D- wires are also ok.

[KhadgaR]

Nice. But you did not mention what benefit you got from your work or why you wanted to do so. I think each usb port needs individual 5 volts to run the device connected to it. Supplying 5 volts to all the usb ports in parallel from a same point is no better achievement. The usb hub with external power supply has individual 5 volts supply to each usb port. As a result, it supports as many devices as the number of usb ports, run together at a time. So, it is the price of the power adapter that makes the price of a usb hub with external power supply expensive.

[Christian RobertA]

Hi!
I read you instructions about this mod.
Im interest, why you cut the vcc which goes to the pc?
The instruction under No. 5 in your to-do list.

That makes no sense to cut the wire actually.
If you leave the vcc which is coming from the PC usb to the hub, and put an external 5v vcc to that wire and the two gnd wires are also connect in paralel, you will have a parallel connection, which will
cos in a higher capacity output of the hub.
Any explanation for the vcc cutting under No. 5?

[msaleiro]

You have to cut it in order to not have two competing power supplies (the PC and the external one). If you have two power supplies trying to feed the same circuit you may end up burning one of them.

[Christian RobertA]

Ok, I don't got the point, sorry.
If I understand you, than, you cant power a device from two separated battery which are in parallel or you can't power a device from two separated power adapters which are in parallel connected?

Where is the big-bang theory here?

[msaleiro]

It depends on the battery technology e charge state. Consider for example two equal Li-Ion batteries. One of them (A) is fully charged at 4.2V and the other one (B) is discharged and has only 3.5V. In the moment you connect them in parallel there will be a sudden flow of energy from battery A to battery B until they reach balanced state, This sudden current is uncontrolled and can cause either battery to burn because of the amount of current involved. Of course, this depends on the battery technology. Some are more sensitive than others. When you think of power supplies the same happens. One may be providing 4.9V and the other 5.1V which means that the 5.1V power supply will be providing energy to the circuit and also into the other power supply which can result in damage to either one.

[AOTN2000]

Thank you for taking time to do this, very helpful.

[msaleiro]

You're welcome. Thanks for your appreciation.

[morrisonsean711]

hey do you think it would be useful to solder a diode in series with the vcc input via usb red wire instead of cutting it so if voltage drop occured due to multiple devices etc, the pc could take up the slack?

[msaleiro]

Could be useful in some cases but I'm not sure if it would help because the diode would impose a 0.7V drop between the PC USB and the actual USB hub circuit. With some devices it could work but with others could cause problems

[AdrianI34]

Hi. I have a 4 ports usb 2.0 hub and it has a power input connector. But I don't have the AC wall adapter! That's how I bought it, without the wall adapter. But now I want to use it with hard drives and they require more power! I found a power adapter with the right plug, BUT it is a 6v and 1000 mA.

My question is: can I use it with my usb hub? Will I have problems with the Hard Drives (as I have important stuff on it)? Is it to much power or too little? Or it is just fine to use it? Thanks so much for help! Great tutorial, by the way!

[morrisonsean711]

if you have a multimeter, you can check to see how close it is,, ive seen power adapters that say 10v and are 14v. if the adapter is a solid 6 or a hair over no worry, there is a hack for that. for every diode that you run in series, you drop about .6 -.7v run a couple of them if you need to, remember that things are designed for almost 20 percent this way or that way as far as voltage goes so you would probably be fine throwing one diode in series with the power positive.

you can do that on the hub, or on the adapter wire itself. or use a usb phone charger and save yourself the hassle.

[T FawazelulR]

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]

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

[AdrianI34]

Hi. I have a 4 ports usb 2.0 hub and it has a power input connector. But I don't have the AC wall adapter! That's how I bought it, without the wall adapter. But now I want to use it with hard drives and they require more power! I found a power adapter with the right plug, BUT it is a 6v and 1000 mA.

My question is: can I use it with my usb hub? Will I have problems with the Hard Drives (as I have important stuff on it)? Is it to much power or too little? Or it is just fine to use it? Thanks so much for help!