USB to DC charging pinout - Hardware Hacking General

Hello
I'm hoping some USB expert can help me out here, I'm trying to make a USB to DC (2.5mm plug) cable that can supply 2A, I have the popular HP Touchpad wallcharger that's rated 5v 2A , so I took a spare quality usb cable (copper cables) it has red, black, green, white (and a big bare metal cable and aluminum wrapping, shielding probably), the DC plug end has two wires red + black, so I hook up red to red black to black (red is 5V black is ground, tested using a multimeter) but I don't seem to be getting as good of results that the stock cable I have gets, the stock cable charges the device at around 1.8 Amps , the cable I made only outputs 800ma to 1.3 amps and if I turn the brightness up it stops charging like it can't supply enough power amps (again stock cable works fine with full brightness).
I'm wondering if on the charger end I need to do something with the green, white wires they both output around 2 volts should these be shorted to the black or possibly red wires to add additional amperage?
I found a youtube video where someone made a similar PSP charger and they spliced both the green, white and blacks wires together, I just want to make sure this is correct way to do things.
youtube.com/watch?v=8WhMeZkrK8U
Btw I also purchased a pre-made cable from dealsextreme but it exhibits the same behavior where full-brightness the charging light dims and goes out on my device, I assumed the low quality of the cable was to blame or again something needs to be connected with the green, white wires.
I know similar questions have been asked before but most have dealt with USB to USB fast charging , with USB to DC I'm confused on what to do with the D- and D+ wires at the charger end should they be shorted together? or to the black cable

ok I think I answered my own question, I tried to do a Ohm test on the stock cable and it seems there was no connection to the green and white or to any of the other wires, since the Ohm reading always returned 0, red and black got a 1+ reading meaning they were connected and a circuit was completed.
Looking at my stock cable it has a big black magnet on it, researching google i found this might be a ferrite core cable, so maybe this somehow boosts the signal and lets the cable pull more amperage or something.

The cylindrical lump on some cables is a ferrite core.
Its purpose is to reduce the amount of logic-generated RF noise from finding its way onto the main span of cable and using it as an antenna.
It will not affect any aspect of charging/powering a device.
Yes, the white/green data pair are used sometimes to indicate a dedicated charger.
A dedicated charger can have more current drawn from it than a normal USB connection.
This subject is handled exhaustively here: http://forum.xda-developers.com/showthread.php?t=1384253

otyg said:
ok I think I answered my own question, I tried to do a Ohm test on the stock cable and it seems there was no connection to the green and white or to any of the other wires, since the Ohm reading always returned 0, red and black got a 1+ reading meaning they were connected and a circuit was completed.
Looking at my stock cable it has a big black magnet on it, researching google i found this might be a ferrite core cable, so maybe this somehow boosts the signal and lets the cable pull more amperage or something.
Click to expand...
Click to collapse
What are you trying to do, make another Touchpad charger? I assume you made sure it can supply up to 2A at 5V.
Many chargers including the HP Touchpad one IIRC short the green and white data wires and this tells the device it can draw more current. If your ohmmeter was reading 0 then that would mean they are shorted. I don't think they are tied to ground (black) just to each other.
The ferrite choke is there to suppress noise from the switching transformer so the device gets clean DC power when charging.

Thanks,
I was trying to make a cable for a Chinese tablet that cannot be charged through it's USB port and only has a 2.5mm dc power port, it seems to be pretty picky about the cable being used, so far the Stock cable to USB-DC to wall USB charger works fine (hp touchpad charger), and a true DC brick rated 2000ma , 5v to DC port works good, I wanted an extra cable to use to charge it with my HP usb charger so I ordered this from dx.com
http://dx.com/p/usb-to-2-5mm-dc-charging-cable-2538
as always I check the polarity and voltage of the cable and it showed 5.13 volts, and center pin positive, strangely when I hooked it to the tablet I saw the battery charging , at 100% I turned brightness up and ran a 3d game, suddenly I saw the red light switch on the tablet to indicate it's charging, strange since it was hooked up to power and was already fully charged, and another test battery was around 40% and I charged to around 80% I rebooted the tablet and the battery was at 40% again!, so thinking my battery died I re-hooked up the stock cable and charged to 80% rebooted again and battery was 80% , narrowed it down to the cheap dx.com cable not supplying enough amps or some short in the cable, this is when I decided to make my own cable.
In my post above, The USB cable I was using I ended up taking apart the usb male connector and found out although the cable was decent quality copper wires.. where it was making the connection at the USB male end the connector only had little push pins puncturing through the wire (two little metal prongs), they weren't soldiered or anything so I guess it was another cheap cable .
So I searched for another cable, finally I found an older usb cable that none of my devices use anymore, this cable actually had a copper metal shield I just connected red and black, left green and white alone not connected to anything, so far it is operating like the stock cable when fully charged I can run full brightness , cpu at fullspeed, and 3d game without the charger light on the tablet going on (I assume this means the tablet is getting enough power from the dc port and doesn't need to switch to battery), I haven't had time to charge the device with the cable yet, but I'm assuming it will work like intended.
I guess they don't make cables like they used to.

hey guys you can check this site out http://techno-fix.com/ . i found my pinout searches there. there are very usefull things

Related

Charge-Error while charging in my ar

Hello Friends,
i made myself a Carholder with Charger and Audio-Connection for my Wizard100. I took a Lm7805 to create +5V out from 12V of the Car Battery. I also took a normal Mini USB Plug, and connected the two wires who leads the Voltage to the unit with my 5V Regulator. When i turn on ignition in my car i could measure the 5Volts at the Cradle and when i plug in my Device the Charging LED goes Red and the Symbol in my Today Screen shows the charging. But when i pull out my Device after a while the batterypower goes down very fast and rapid. Why? Is there any conection that has to be done? How many pins are used to charge the Wizard by USB?
Charging current...
How much current is your rig capable of, the stock charger puts out 1 Amp. I know that the wizard is rather finicky 'bout its charging method. Hope this leads you in the right direction...as for pins, i would think that if it says its charging, then your pin outs are ok. It would most likely be about the amperage
The L7805 Regultaor IC fits up to 1.5A .Thats enough i suggest. Now i´ve ordered a real car charger and put the electronic in my carholder. What about grounding? Is ist allowed to put the Audio Ground together with the charging ground or must I divide both grounds?
Thanks so far for your replys...

Kensington 4-port Charger and Treo Pro

Does anyone have experience using 3rd party chargers with the Treo Pro or HTC devices in general?
I've purchased a kensington 4-port USB wall charger. It's an interesting concept which allows you to plug in up to 4 USB cables (iPods, iPhones, Treo Pro) and only use one outlet. A neat trick when you have multiple phones and devices in your family.
My problem is that the kensington won't charge the Treo Pro. When I plug it in, the LCD lights up, but the charge indicator does not appear nor does the tone sound that it has been plugged in. Note, as far as I can tell the Treo Pro charger outputs 5v DC exactly the same as the Kensington charger.
I've read several posts that lead me to believe that HTC does something to their devices that only allow certain chargers to work or that their USB cables have a certain pin-out that allows them to charge. Anyone have any advice?
Thanks!
Well, I got my wall charger and car charger from Officemax. The charger brand is "Just Wireless". Both are working fine for me. Before, I tried to use the sync cable to plug the regular USB power adapter for wall or car charger, some work, some don't. It seems Palm modified the micro-usb cable...
So my suggestion, if you are looking for charger for Treo Pro, you should look for compable with Moto R9 (which using micro-usb plug, too) I used to have one Moto charger, It worked in my Treo Pro!
jbinmn said:
My problem is that the kensington won't charge the Treo Pro. When I plug it in, the LCD lights up, but the charge indicator does not appear nor does the tone sound that it has been plugged in. Note, as far as I can tell the Treo Pro charger outputs 5v DC exactly the same as the Kensington charger.
I've read several posts that lead me to believe that HTC does something to their devices that only allow certain chargers to work or that their USB cables have a certain pin-out that allows them to charge. Anyone have any advice?
Click to expand...
Click to collapse
There's really nothing "special" going on here. It's all in the USB spec. http://http://en.wikipedia.org/wiki/USB#Power
That said, there are few other devices that demand a dedicated charger (or a communicating host), so in that sense it is special.
The problem being that the TP won't draw more power than agreed upon with the host (or in this case the carger). And since your charger doesn't tell the Treo that is has power to spare, the Treo trying being a good little device won't start charging.
Now, for the charger to tell the Treo that it is, in fact, a dedicated charger and "go ahead, draw as much power as you want up to 1.8A" it would only have to short its data pins.
Now that is something YOU could do to get the charger to work with your Treo. Either open the charger and solder the data pins (the two middle ones in a normal sized usb socket). Or if you can't for some reason, slice a micro-usb cable open and short the two data (usually the thinnest (green/white maybe)) wires inside.
I got a couple of desktop chargers from ebay for about £8 each. Work fine.
frause said:
There's really nothing "special" going on here. It's all in the USB spec. http://http://en.wikipedia.org/wiki/USB#Power
That said, there are few other devices that demand a dedicated charger (or a communicating host), so in that sense it is special.
The problem being that the TP won't draw more power than agreed upon with the host (or in this case the carger). And since your charger doesn't tell the Treo that is has power to spare, the Treo trying being a good little device won't start charging.
Now, for the charger to tell the Treo that it is, in fact, a dedicated charger and "go ahead, draw as much power as you want up to 1.8A" it would only have to short its data pins.
Now that is something YOU could do to get the charger to work with your Treo. Either open the charger and solder the data pins (the two middle ones in a normal sized usb socket). Or if you can't for some reason, slice a micro-usb cable open and short the two data (usually the thinnest (green/white maybe)) wires inside.
Click to expand...
Click to collapse
Hi!
Yep i just bought two kensington 4 port chargers and looks like it doesnt charge the TP
Im about to buy a microusb cable to do the trick you suggested, (i cant seem to open the Kensington 4 port!), any reference websites you could suggest that could explain abit more about the shorting of the data wires inside? Just like to read up abit more before the cable arrives
Thanks!
shorting two center pins solves problem
Thank you for the details. I was able to get two car chargers to work with Palm cables after opening them up and shorting the middle pins with a dab of solder. I opened up a non-Palm cable and discovered only two wires, red and white, and no surprise: it did not work even with the "fixed" adapters. So you need to have pins shorted, and a cable that can return the short to the Treo from the adapter, or if you have a cable with all leads inside you could short the two wires instead and leave the adapter alone. However, if you only have two wires inside the cable you would have to short inside the micro plug, which is a little cramped to work in. If you have only two wires in your cable (hard to tell really without cutting it open; too small to get a continuity probe in there), and/or an adapter without the pins shorted, the Treo will not pull current and charge itself.
The Wikipedia USB Spec referenced by frause above says in part:
" A Dedicated Charging Port can supply a maximum of 1.8*A of current at 5.25*V. A portable device can draw up to 1.8*A from a Dedicated Charging Port. The Dedicated Charging Port shorts the D+ and D- pins with a resistance of at most 200O. The short disables data transfer, but allows devices to detect the Dedicated Charging Port and allows very simple, high current chargers to be manufactured."
An interpretation of the reported observations and this spec is that a charger can communicte to the device under charge the maximum current the charger is able to supply. This communication occurs by the charger either "shorting" the data pins or not. Non-shorted data pins indicates that the charger is capable of at most 500 mA. Its possible that the Treo Pro(TP) is smart enough to know it should conserve power when being charged from a low current charger. One way for the TP to conserve power would be to not power the LED on the TP if there is only 500 mA available for charging.
NOTE THAT IF THIS INTERPRETATION IS TRUE THEN IT IS ACTUALLY DISADVANTAGEOUS TO ARTIFICIALLY SHORT THE DATA PINS.

Emergency charger and Tytn II

Hello, I've just bought an emergency charger for my Kaiser. It takes the power from an AA battery and gives the USB voltage in the output. It works great with my Mio A 501, but doesn't work at all with the Kaiser. I did a quick search and found this in a discussion about car chargers:
Are you using the HTC charger or an OEM one?
The HTC charger works all the time the OEM ones don't - the reason being that if you use a normal Mini USB cable, the handsets will only take a charge if there is an indication of a data connection (either than gprs or the cable) - otherwise it won't take a charge.
You can apparently solder a couple of wires together on a normal mini USB cable - but I wouldn't know where to start on that!
Click to expand...
Click to collapse
Now I've already heard of that, for example, a Play Station Portable needs the data wires in the USB grounded in order to charge. Is it the same with Kaiser? (putting three wires together isn't a big deal) Or is there an easier way how to make it charge?
So, I gave it a try and soldered the data wires with the ground wire. But when I try to charge the Kaiser, a yellow led starts to glow (which it didn't with the original cable) and, after a minute or two, the led goes off and Kaiser stops charging. When I turn the Kaiser off and then plug the cable in, the yellow led doesn't go off. However, when I turn Kaiser back on to check the battery meter (after about half an hour), I find out that the battery didn't take any charge at all. So, could anyone tell me what the problem is?
thanks, Mike
PS.: Adding some photos of the wires...
Probably because of the voltage...
Hey!
Have you checked the output voltage of this charger? Standard charger outputs 5V. If yours outputs less - the battery won't charge; if outputs more - you may "burn" your PDA chipsets
5V - 5.5V is safe range.
I found this on thinkgeek.
http://www.thinkgeek.com/gadgets/cellphone/b43f/
It says for iPhone, but sure it would work just fine with other devices that have issues.
had a same problem but using it in the car...
when i got my tytn2 i immediately bought a car charger and the salesman told it's an original one, said output 5v 1A.. when using in the car it charged for a minute or two and went off... than i got from ebay a micro usb 1A charger (used for iPhone too) and tried in the car-> it work flawlessly

Usb charge

Hi. I've solved the problem of using other chargers with GT.
Like Apple, Samsung used a little trick with their chargers.
To charge your GT with any usb charger you have to make a little adapter.
Usb pinout:
gnd d- d+ 5v
To work you must short d+ and d-.
From 5v use a 33k resistor to d+/d-.
From gnd use a 10k resistor to d+/d-.
If you have multimeter you should obtain ~4v between 5v and d+/d-; and ~1v between gnd and d+/d-.
I tested it and it's working.
Hi, it's not a trick but a standard. You only need to short d+ with d-, the resistors are not needed. Just be sure that the charger outputs closest to 5v possible, around 5.2~3 usually work for everything. About 5.6v and it start not to work on some devices, like apple..
Maybe, I have to test that
I know it's not a trick, I should wrote "trick".
For example GT adapter outputs 5.31v.
Apple adapter worked with 1 22k resistor between d- d+.
WarlockM said:
Hi. I've solved the problem of using other chargers with GT.
Like Apple, Samsung used a little trick with their chargers.
To charge your GT with any usb charger you have to make a little adapter.
Usb pinout:
gnd d- d+ 5v
To work you must short d+ and d-.
From 5v use a 33k resistor to d+/d-.
From gnd use a 10k resistor to d+/d-.
If you have multimeter you should obtain ~4v between 5v and d+/d-; and ~1v between gnd and d+/d-.
I tested it and it's working.
Click to expand...
Click to collapse
WarlockM said:
To charge your GT with any usb charger you have to make a little adapter.
Click to expand...
Click to collapse
How can you do that? You need an extra device adapter? Please explain.
I've tested with d-/d+ shorted and it's not working.
@MizGarfield if u have 1 usb extension cable u can cut it on half.
Tie together white and green wires.
Tie black wires and conected to that 1 end of 10kohm resistor, the other end tie it to green/white wire.
Same to red wires but use 33kohm resistor.
See att. Sry for drawing.
bookmarking this for later use
WarlockM said:
I've tested with d-/d+ shorted and it's not working.
@MizGarfield if u have 1 usb extension cable u can cut it on half.
Tie together white and green wires.
Tie black wires and conected to that 1 end of 10kohm resistor, the other end tie it to green/white wire.
Same to red wires but use 33kohm resistor.
See att. Sry for drawing.
Click to expand...
Click to collapse
You don't need that for modern devices has i told you. It did not work because you did it wrong. I have all my usb chargers working the new way, you even have wikipedia talking about it. You have to cut the data + and - on the power supply from the female usb port and short only the female d+ and d-. Trust me it works and it is alot simpler.
Edit : from wikipedia "The Dedicated Charging Port shorts the D+ and D- pins with a resistance of at most 200 Ω. The short disables data transfer, but allows devices to detect the Dedicated Charging Port and allows very simple, high current chargers to be manufactured. The increased current (faster, 9 W charging) will occur once both the host/hub and devices support the new charging specification."
""As of June 14, 2007, all new mobile phones applying for a license in China are required to use the USB port as a power port.[35][36] This was the first standard to use the convention of shorting D+ and D-.[37]""
http://apple.slashdot.org/story/10/08/03/1743240/Hardware-Hackers-Reveal-Apples-Charger-Secrets
""We all love to call out Apple when they design deliberate incompatibility into their devices, but there is a perfectly valid technical reason for what Apple is doing here, and, in fact, they are following a USB specification (which LadyAda unfortunaterly didn't even test).
Without data communications or when suspended, devices may legally draw no more than 2.5mA from a host, which is useless for charging. In fact, even if you're generous and pretend they're connected, devices are not allowed to draw more than 100mA without negotiating for a higher current, which requires actually talking to the host, and 100mA is still too little to charge properly. 500mA is the maximum allowed by the USB spec, but devices must negotiate it (there may be too many devices on the bus for negotiation to succeed).
Before there was a spec for "dumb" USB chargers, Apple used the resistors as a sentinel to avoid drawing too much current from undersized chargers in order to avoid damaging the host. This is a hack, but it works, and honestly, we're smart enough to figure out a couple resistors on the data lines. It's not like they're using crypto auth on the charger. They have a perfectly valid reason to do this. Devices which charge from "dumb" chargers aren't following the spec, though this is a common industry practice.
As it turns out, the USB-IF came up with a USB Battery Charging spec [usb.org]. The spec is long and boring, but it boils down to: short together the data lines (no resistors required) and you indicate that you're a dumb charger that can supply anywhere from 0.5A to 1.5A.
Guess what happens when you short the data lines of an iPhone 3G and supply 5V [marcansoft.com]. Did Apple just follow a standard? Incredible!
(Yes, I'm not following the USB spec there by in turn using a USB cable to supply the 5V and not negotiating over its data lines. I didn't feel like grabbing a dedicated 5V PSU for the shot, so sue me.)"""
http://marcansoft.com/transf/iphonechg.jpg
ok ??? no need for resistors, only 5.3V MAX and d+ and d- shorted
Thnx for the tip gonna try this later on my sanyo eneloop power booster tried it yesterday without this mod and it doesn't charge so gonna look for a AF to AF converter and modify it to gound the D+ and D-
@adolfotregosa
I tried again shorting d-d+, with iphone it works but with GT it's not working.
I use BatteryWatch and it is saying Not Charging. It's detecting the connection like usb port but is not. I use some device build by myself with 1 amp capabilities. D- and D+ r free of any connection and i can do with them what i want.
I dont say you r wrong but it's not working with GT.
Sent from my GT-P1000 using XDA App
but smt is wrong on your custom setup, voltage ??
EDIT: i just measure the original charger and it has no resistance between the data and power pins.
I think i know what could be wrong, when you plug in the Tab and it says not charging, how many volts have you got at that time ?
The original charger is very good because when it not charging the tab it has 5.3x volts but when you plug it in it lowers to 4.8x V Max and that is very good ! most chargers tend to lower much more (bad quality or just not powerful enough) and that is what causes the not charging messages on the tab or other devices.
Well i rest my case on this.
My device with no load it have 5.21v and with load 5.03v so it's not from him and i have another supply 5v/12 amp and it's doing the same (not charging, only with data shorted).
When u r trying to measure the original ps u can read ~7k between gnd and data but from 5v to data u cant because it have some capacitors.
Maybe samsund did something else, i have to try, maybe data pins drawing some current (mA) and that's why it's not working with only shorting them.
For the moment it's the only (working) solution i've found and i'm happy with it .
P.S. If i'm not finding anything else the last resort will be to open the original ps
Sent from my GT-P1000 using XDA App
USB Charger
This is what worked for me.
Items Needed:
USB Extension Cable
33k-Ohm Resistor (Shack Part No. 271-1129)
10k-Ohm Resistor (Shack Part No. 271-006)
Steps:
1. Cut USB Extension Cable in half, lets name the 2 halves, the half you will plug into the power suppy will be called "Cable A" and the half that you plug into the Galaxy Tab Data Cable will be called "Cable B"
2. On 'Cable A" strip outer plastic to expose all wires within, eliminate Green and White on this cable only as it will not be needed, leaving you with only the Red and the Black Cables
3. On "Cable B" strip outer plastic to expose all wires within, this should leave you exposing all 4 wires
4. On "Cable B" strip both the Green and White wires and join thes 2 wires with the 2 resistor ends (you should be using the resistor ends that have the red band with these wires), these can be joined by either soldering or just twisting together.
5. Strip Red wire from both cables and join together with the 33k-Ohm Resister (this will be the larger of the 2 resistors and should also be the end with the Gold Band) and as well join these together with solder or just twisting together.
6. Repeat the above process with the Black wires and 10K-Ohm Resistor.
7. No finally use Electrical Tape or Shrink Tubing to cover all your work.
This worked using it on a Champtek 5v 2.1a USB Car Charger and Home Charger. Also worked with iPhone charger. Also works with Original Galaxy Tab.
Hope this helps out.
May I just ask some clarifying questions?
rick75204 said:
This is what worked for me.
...
4. On "Cable B" strip both the Green and White wires and join thes 2 wires with the 2 resistor ends (you should be using the resistor ends that have the red band with these wires), these can be joined by either soldering or just twisting together.
Click to expand...
Click to collapse
Does it matter WHICH resistor you join to which of these two wires?
rick75204 said:
5. Strip Red wire from both cables and join together with the 33k-Ohm Resister (this will be the larger of the 2 resistors and should also be the end with the Gold Band) and as well join these together with solder or just twisting together.
Click to expand...
Click to collapse
So that you have effectively bridged the red wire with 30K-Ohms to one of either green or white running to the TAB?
rick75204 said:
6. Repeat the above process with the Black wires and 10K-Ohm Resistor.
Click to expand...
Click to collapse
And bridged the black wire with 10K-Ohms to the other of either green or white running to the TAB?
Would this be an accurate picture, with the 33K Ohm Resistor on the left, and the 10K Ohm Resistor on the right?
I think the intention was that you short the green and white wires together: so you are connecting both wires to both resistors.
That way the two data lines are both held at a fixed voltage of about 1.2V
Thanks, that clarified it.
I noticed today that if I connect my Tab to my keyboard (standard Apple USB KB with keypad, connected to a circa 2006 iMac), the device started charging according to battery stats. When it was plugged in it was at 48% and it ended up at around 60% after a few hours. Am I being deceived or something? I was under the impression that it would only charge if connected to the mains charger. Well I guess I'll see how long it runs now it's off the leash and see if it lasts till the morning (left my charging cable at work - D'oh!).
No, it definitely does charge even when it says it isn't - just slowly. I've got a 2A non-official USB charger that charges it up pretty quick, but still says it isn't charging. If the screen is off, it will even charge off one of those tiny Kindle chargers that must be delivering less than 500mA, but *really* slowly.
Clarify
Sorry guys, only a clarification.
As far as i understood:
the GT DOES charge with *any* charger (or connection to PC);
if you use the original charger (2Amp), it charges showing the charging-icon;
if you use a non-original charger, it charges in any case but NOT showing the charging-icon and depending on the charger power (even 1Amp charges, or 500mAmp, *VERY-REALLY* slowly);
if you use a non-original charger with the two resistors (33k + 10k) it charges showing the icon (even with a 1Amp).
Can anybody confirm if i understood well?
Thanks!!
eiem said:
Sorry guys, only a clarification.
As far as i understood:
the GT DOES charge with *any* charger (or connection to PC); Yes but slower than the original charger
if you use the original charger (2Amp), it charges showing the charging-icon; Yes, exactly
if you use a non-original charger, it charges in any case but NOT showing the charging-icon and depending on the charger power (even 1Amp charges, or 500mAmp, *VERY-REALLY* slowly); Yes.
if you use a non-original charger with the two resistors (33k + 10k) it charges showing the icon (even with a 1Amp). Depends, i get various results even though i am using the mod since day 1.
Can anybody confirm if i understood well?
Thanks!!
Click to expand...
Click to collapse
Thats it for now.
It seems that the Tab could recognize the status of the usb connection by measuring the usb data rx/tx wire level. If it is not shorted, the "pluged in but not in charging" status will appear, as the mismatch voltage of the usb connection is made.
Sent from my XT701 using XDA App

Nexus 7 Car Charger Issue

Hey all, quick question.
I have my Nexus 7 installed in my car. Originally it was getting power from a 500mah USB car charger, but it didn't provide enough power to the tablet when running GPS/maps, etc.
So I bought an "8Ware Dual USB Car Charger 5V/2A" to try. I plugged it in, and the tablet doesn't detect it or charge from it. However I can plug my Galaxy S3 into it and it charges fine.
Really confused about this - it makes no sense.
Any ideas?
Thanks in advance!
I understand your frustration and it sucks!!
But sometimes even when it says UNPLUGGED and NOT CHARGING, just leave it there for 30-60 minutes. You might see that your battery actually increase... This happens with my Griffin PowerJolt Dual USB car charger also.
You can either blame the device or you can start blaming other issues like the charger, the usb cable etc but for me, I blame primarily on the device.
- Charles
chaddeus said:
I understand your frustration and it sucks!!
But sometimes even when it says UNPLUGGED and NOT CHARGING, just leave it there for 30-60 minutes. You might see that your battery actually increase... This happens with my Griffin PowerJolt Dual USB car charger also.
You can either blame the device or you can start blaming other issues like the charger, the usb cable etc but for me, I blame primarily on the device.
- Charles
Click to expand...
Click to collapse
Thanks for that. I tried plugging it in for a while but it definitely didn't get a charge.
Hey All.. I looked forever to find a solution. The Targus 2A car charger has a small (3") adapter cable that comes with it purportedly for Galaxy Tab. That little cable with the data wires shorted on the device end allows the N7 to be charged from ANY 2A car charger. I'm using the adapter with a Scosche dual 2.1 Amp Car Charger
Adapter picture
Targus Charger
Edit: I just built a usb cable with the data wires shorted on the Nexus end (cut, strip, short micro usb end green and white, remake connections red to red and black to black, insulate splices individually, wrap all in electrical tape or heat shrink for strength and beauty) and it works with all chargers. Took about 20 minutes.

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