USB Cell Phone Charger Hack! (With Video)

Here is an EZ to make, no frills, USB Charger for your cell phone. Great for anyone on the go. Add it to your "mobile goodies". Just in case. Video to follow...

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Step 1: What you need

$C:\Downloads\usb1.jpg$

1. Standard USB Cable
2. 12v Cell phone car adapter
3. Wire Strippers
4. Solder
5. Shrink Tubing
6. Voltmeter

sugotech says: Mar 5, 2012. 12:30 AM

its nice post, i have also do it but not with it i have done it with charging lite.

Bus213 says: Jun 8, 2009. 1:02 PM

Could please someone explain me why it does not work with nokia 6061? I did "exactly" as in the instructables, but as others I receive the message "NOT CHARGING". I know that my wall charger output is 5.7V 800mA and the battery requires 3.7V. So what is different?

martzsam in reply to Bus213Oct 16, 2010. 8:18 PM

I realize this question is really old, but it's because some phones won't charge unless the feel a small charge from the wires that carry information.

serith says: Nov 27, 2009. 4:58 PM

I did something similar; I took an old ipod connector cable, cut it, found the positive and negative wires and hooked the end with the connector cable to a 6v 4AA battery pack, and took it down a half a volt via resister.

I then strapped it to the back of my ancient (really, it's a dinosaur) ipod. If I have time I will post pics.

Crail says: Oct 28, 2009. 8:17 PM

agh cheater! you have only two!

kidding
but really, what do I do if I find 7 wires instead?

Tropicana says: Oct 7, 2008. 6:22 PM

Works perfectly fine on my Samsung SCH-N370 Battery doesn't even get hot.

ddvniek in reply to TropicanaOct 17, 2009. 10:29 PM

So it worked on your Samsung phone. I have a Samsung GT-S5233A (Star). Do you think this will work on my phone? On my cellphone charger it said that the output is 4.75V.

vptony says: Jun 12, 2009. 1:32 PM

this didnt work for me my wall charger is 5v my usb cable has red green black and blue wires and my phone plug red and white and red to red and white to black dont work phone shuts off compleatly and wont turn back on unless i unplug it? any ideas?

Smokedasphalt says: May 29, 2009. 5:17 AM

What is the value of the current??

Mr_Christopher says: Mar 9, 2009. 1:57 AM

For those who had mismatching colors when splicing cables, just remember that the main goal is to connect positive to positive, and negative to negative. In my experience messing around with stuff like this, I have observed that common colors for power wires in electronic cables (in order of common use) are: Positive: Red, White, Green Negative: Black, Gray, Blue Note that for USB, the standard would dictate there be four cables: Red, Black, White, and Green. White and Green in that case are for data, and Red and Black are Positive and Negative, respectively. So, for example, if you have one cable with Red and White wires, and another with Red and Black, connect Red to Red and White to Black. This should work ok, but if you get no response, switch them around and try again; the voltage is low, and unlikely to cause damage.

JussyfOgs says: Nov 28, 2008. 8:11 PM

on your phone charger somewhere there is the specifications of the charger, I don't know about all of them but the Nokia charger uses 5 volts. so just check your wall charger first.

Fommy_usa says: Nov 4, 2008. 2:08 AM

Two types of chargers are wall chargers to plug into the wall and car chargers to plug into your car's cigarette lighter.
g1 accessories

sumasbrod says: Sep 22, 2008. 11:44 AM

Nice thing, but not working with my nokia 5140 — just saying "not charging"...i wonder why it is so, because 220v charger provides less curent than USB...but working OK with 3310! )))

lathmos says: Aug 20, 2008. 7:42 PM

cool instructable, but my phone uses a standard usb cable to charge, so I can skip all but step 1 :)

Head Wound says: Jul 29, 2008. 1:57 PM

Kipkay, I liked your USB charger project, I took the basics of your charger and adapted it to apply to other hand held electronics.

sardines454 says: Jun 21, 2007. 3:18 PM

help needed, ok, i got the usb cable and was able to strip one end, when i put the black and red wires on a small motor it turns, then when i stripped my phone charger i found a red and white cable, red on red and black on white didn't work. anyone know why?

Head Wound in reply to sardines454Jul 29, 2008. 1:53 PM

As in the video Kipkay tested the wires with a volt meter, not all cables use the same coloring. Try using a volt meter for checking polarity, current and continuity. Also it does not hurt to double check your connections you just soldered.

Yerboogieman in reply to sardines454Feb 24, 2008. 6:48 PM

use black to black, red to red

Derin in reply to YerboogiemanJun 25, 2008. 11:09 PM

no he is trying to say he had red and white cables on the phone charger

andrew101 in reply to sardines454Jul 29, 2007. 10:13 PM

whats your phone voltage?

sardines454 in reply to andrew101Jul 30, 2007. 9:45 AM

my wall charger says 5.7v and the battery in my phone say 3.7v

andrew101 in reply to sardines454Jul 30, 2007. 10:43 AM

hmm thats strange since your charger is 5.7 it should work does it still work with the wall adapter?

Derin in reply to andrew101Jun 25, 2008. 11:08 PM

it should work i have a nokia like that which works

Kipkay (author) in reply to sardines454Jul 30, 2007. 10:31 AM

Then the phone has a built in regulator that will regulate the voltage going to the battery.

andrew101 in reply to KipkayJul 30, 2007. 10:46 AM

um that doesnt tell why its not working! his charger is 5.7 volts if it had a regulator it would just lowerthe voltage slightly usb is 4.9 volts it is fairly close so it should work just fine the voltage regulator wouldnt stop it form working in these conditions

sardines454 in reply to andrew101Jul 30, 2007. 11:50 AM

it is strange but once i plugged the usb charger in the phone restarted and refused to charge, luckily it was still under warranty so I got a free replacement!

furcino says: Sep 21, 2007. 11:24 PM

I do not know what you guys have for phones, but mine usually used about 3.7V or !!!LESS!!! (2 Boshs, 2 Erricsons, 2 Nokias, 1 Motorolla - I checked the voltage because of a project I made.)

Check the battery first! I certainly would not try this one out.

Head Wound in reply to furcinoJul 29, 2008. 1:50 PM

Yes most cell phone batteries are 3.6 to 3.7 volts but the voltage you want to look at is out much the out put is on your Charger/ adapter. Vast majority of cellphone chargers are approx 5 volts. Hence check your charger and not your batteries.

Derin in reply to furcinoJun 25, 2008. 11:11 PM

my battery is 6 volts

_NiMH

Redgerr says: Jul 20, 2008. 12:33 PM

lol, why there a cat in almoest all of your video's :) very ammusing :D

Waterpolo93 says: Jul 2, 2008. 1:08 PM

this was exactly wat i was about to do rite now i thought it up last nite while texting but now y beat me to it!

ferny121 says: Jun 10, 2008. 6:35 PM

you better belive this works. i tried it and it worked like a charm. great instructable.

ptfuzi says: May 3, 2008. 11:20 AM

i tried to do that..but in my phone it says "not charging" have you any idea what's wrong?i checked voltage too

arsim4ever in reply to ptfuziJun 6, 2008. 7:01 AM

same problem here. My wall charger voltage is 5.3v. My phone umm.. i dont know.. how to fix this? tq.

UrmiRaj14 says: Apr 12, 2008. 12:49 AM

Hi Kipkay i just want to say thanks thank so much for having this video. in my search for a usb-powered cell phone charger for my se k790i i came across this site and made it my weekend "wanna-try" And it works!! love this and def made my weekend :-D

miss.charlotte says: Mar 24, 2008. 3:48 PM

About a week ago I lost my cell phone wall charger at school and didn't have the cash to buy another. My bf gave me a car charger for my phone, but seeing as how I don't have a car, it didn't do me much good at home. I'm so glad I found this instructable! I took apart the car charger, usb cord, and twisted the wires and wrapped it up in some electrical tape. Wonderful! It definitely keeps my phone charged and much better than the car charger did! Yayy!!!

fred531 says: Mar 2, 2008. 3:02 PM

About the voltage issue: would it not just be easier to strip some wire close to the car charger while it's plugged in and measure that, so you can later use resistors to match?

Kent says: Dec 17, 2007. 7:50 AM

The charger voltage must be higher than the battery voltage, or you can't get current to flow into the battery. There is always some kind of regulator on Lithium Ion batteries. What voltage it can handle varies. Also, some phones, like recent Motorola types, use a mini-USB cable to charge, but not just any cable. It won't work with this hack. They put a resistor from pin 5 to ground, not for any electrical reason, but to act as a signal that this is a genuine overpriced charger. The circuit tests for the resistor, and will not use the charger if the resistor is not there. It will say, "Unauthorized charger". The value of the resistor varies with the model. You could get around this if you could get a mini USB plug to wire yourself, but they are hard to find.

Yerboogieman in reply to KentFeb 24, 2008. 6:45 PM

i used an older phone that took 5v and charged it with straight 7.2 volts before but those razr phones are harder you have to take a 1k resistor and put it between the black and X wires on the mini usb

maddog81 says: Nov 16, 2007. 12:37 PM

You all need to check the DC output on your wall chargers. Both of the chargers for my cell phones (Nokia 3589i and 6315) and my Motorola bluetooth headset are all 5V DC, which USB ports run at. That is how I figure it's safe to use the USB port to charge the phone. If all else fails, try it on a junk phone first. I do not know if this is correct, but it makes sense to me. I am all for making things myself, if I can do it. The cable I had originally was a USB cable I bought at a dollar store for my 3589i. I chopped off the plug and put a mono 3/32 inch socket on the end. I have some adapters from a Turbo Charger device I have that I use on the cable. Thanks for the tip!