force usb charging - Galaxy Tab 7.7 General

I would like to charge my SGT 7.7 with the normal USB cable it came with on my pc; however, due to its lower mA output (USB standard is 500mA). The standard adapter it came with has 2000mA (2A) output, hence it detects and charges. However, I do notice that the unit charges at 1A with my iPhone charger, perhaps just a bit slower.
Anything we can modify in the rom to enable force usb charging? there is such a way in SGT 10.1 but I can't find a method similar to it on my 7.7

it charges when the device is in a powered off state... but very slowly

onicrom said:
it charges when the device is in a powered off state... but very slowly
Click to expand...
Click to collapse
Yep, it does.
But I would like to keep my device on while charging...

it's very slow because device detect voltage in data line. check out adapter in ebay.
Sent from my GT-P6800 using xda premium

zoftdev said:
it's very slow because device detect voltage in data line. check out adapter in ebay.
Sent from my GT-P6800 using xda premium
Click to expand...
Click to collapse
Yeah understood.
I'm using the Galaxy Nexus USB charger and it works well (1A)
but the iPhone 4S charger does not (also 1A)

kazuni said:
Yep, it does.
But I would like to keep my device on while charging...
Click to expand...
Click to collapse
Mine still charges even with the red X on the battery icon. Albeit, very slowly, and only really when the screen is off. Not bad for just listening to music while I'm at work!

USB charge adapter
To charge your GT7.7 using a usb cable you need to have an adapter.
You can make an adapter from the below parts. See attached images of the end result.
user rick75204 explains it best below.
http://forum.xda-developers.com/showthread.php?t=845844&page=2
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.

USB Charging
Hi Guys
I recently bought a "Samsung Charging Adapter" from power gorilla for use with their portable power packs.
It is a usb adapter which when used in line with the Samsung USB cable, charges my 7.7 while I am using it from a 500ma USB port on my MAC ....
Philip

This works great for $7, has a switch to go from data to charging
http://item.mobileweb.ebay.com/viewitem?itemId=160709394617

how do you force charge on Galaxy Tab 10.1??

razorwokid said:
how do you force charge on Galaxy Tab 10.1??
Click to expand...
Click to collapse
Wrong forum Look in 10.1 development forum, in the thread for pershoot's kernel. Or buy one of the cables mentioned above.

morkli said:
Wrong forum Look in 10.1 development forum, in the thread for pershoot's kernel. Or buy one of the cables mentioned above.
Click to expand...
Click to collapse
Thanks for the response

I have similar charging problem with the stock data cable, but I could be able to charge with a USB 2.0 mini USB cable with a Galaxy Tab to mini USB convertor as shown below.
And I even use an USB extension and it is charging up just fine.

I just ordered this
http://www.ebay.com/itm/Micro-USB-t...-Galaxy-Tab-P1000-7500-7510-730-/170969489675
for $2.99 I hope it works. The things we go through in order to be not price gouged..

I have an existing HDTV (HDMI) adapter and its charging well with the included usb data cable of 7.7. :good:
http://www.samsung.com/us/mobile/galaxy-tab-accessories/EPL-3PHPBEGSTA
Although if you don't have it, it's not practical to buy one just for your usb cable to work for charging.

kazuni said:
I would like to charge my SGT 7.7 with the normal USB cable it came with on my pc; however, due to its lower mA output (USB standard is 500mA). The standard adapter it came with has 2000mA (2A) output, hence it detects and charges. However, I do notice that the unit charges at 1A with my iPhone charger, perhaps just a bit slower.
Anything we can modify in the rom to enable force usb charging? there is such a way in SGT 10.1 but I can't find a method similar to it on my 7.7
Click to expand...
Click to collapse
also would like to know how to force charge via USB I have gigabyte mainboards that have special charging ports that have 3x normal power .. but still can not get them to recharge my galaxy note 2 while its being used :S
strangely my old laptop with USB Ver 1 .. recharges the phone when in use ...
using Ubuntu and unsure if its pc sided software issue or android related issue

The device will certainly charge slowly via USB, although the battery animation may not show it.
You may use other adapters etc, but I'm fairly sure they don't actually work due to kernel limitations. Changes may need to be made within the kernel (same as SGS2) to actually increase actual charging current. SGS2 was set at USB 450mA. I'm sure I've seen the mod while searching github kernel source code.
Some of the measurement apps out their are quite inaccurate, and I have only used as I guide.
You could use init.d script to set on boot, but anything larger than 450mA could be just placebo,.... unless kernel enabled....
If I'm wrong, please correct me.
Sent from my GT-I9300 using xda premium

Simple solution turn off ur tab then connect it to laptop/pc mac/imac it will charge normally
Sent from my GT-P6800 using xda premium

khanfuze said:
I just ordered this
http://www.ebay.com/itm/Micro-USB-t...-Galaxy-Tab-P1000-7500-7510-730-/170969489675
for $2.99 I hope it works. The things we go through in order to be not price gouged..
Click to expand...
Click to collapse
This is garbage. I had three of them and they all broke within a month.
This is what I use now. Built to last.
http://www.amazon.com/gp/product/B009I4HEOO/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

Related

Faster USB charging?

Just got a new motheboard which has high output USB charging for iPhones, pads etc.
Can this work on N1 ?
http://gigabyte.com/MicroSite/185/on-off-charge.htm
edit: driver link is at the bottom for all the hackers. Hopefully its just changing string from apple to android hehe
kazprotos said:
Just got a new motheboard which has high output USB charging for iPhones, pads etc.
Can this work on N1 ?
http://gigabyte.com/MicroSite/185/on-off-charge.htm
edit: driver link is at the bottom for all the hackers. Hopefully its just changing string from apple to android hehe
Click to expand...
Click to collapse
Hopefully not, I dont want my nexus one to be iphone.
But as you know nexus one is using qualcomm motherboard.
But aslong cyanogen and fm transmitter is working there is no problem wiith your phone.
Dear lord what a crappy reply. Stick to disney mate.
It should, it basically just converts the USB port from .5 amps to 1 amp, like a wall charger.
elkyur said:
Hopefully not, I dont want my nexus one to be iphone.
But as you know nexus one is using qualcomm motherboard.
But aslong cyanogen and fm transmitter is working there is no problem wiith your phone.
Click to expand...
Click to collapse
WTF??? May want to lay off the halucinogenics
elkyur said:
Hopefully not, I dont want my nexus one to be iphone.
But as you know nexus one is using qualcomm motherboard.
But aslong cyanogen and fm transmitter is working there is no problem wiith your phone.
Click to expand...
Click to collapse
lol I seriously hope this is a joke!
I agree with JCopernicus, it should definitely work.
I installed the software in the first post but it still charges very slow compared to wall outlet
Slightly OT, but I've got a USB adapter that plugs into the wall that came with my iphone and when I plug the N1 USB cable into this to charge the N1, it still charges very slowly compared to using the proper wall adapter, why is this? Does this iphone adapter restrict the voltage or something?
Generally, "charger detected" is a circuit that has USB data pins shorted together. So when the phone's USB device probes the lines and detects them shorted, it knows it's connected to a power supply.
But since USB max current spec is 500mA, the current draw is restricted - either by the phone or by the supply.
There might be some other connectivity trick that allows the phone to know it can draw x2 current from the socket and won't damage anything. Most phones probably don't limit the current draw and count on the board to do it. Some boards don't limit the current output, or limit it higher. And the fast chargers provide pulsing voltage - which isn't like USB.
So for the board to be able to charge the device, it needs to detect a device that can use pulsing voltage, and enable such voltage on the socket. It doesn't detect Nexus as such a device, I believe, and that's why the charging is slow.
Faster charging with USB
Building on Jack_R1's response, I believe that the phone is limiting the charge rate. You can make the phone "realize" it is connected to a charger rather than a data connection by shorting the 2 middle USB pins together. I have done this in several car chargers, and the N1 About/Status shows charging (AC), which is the faster charge mode. While you can short the pins in the larger end of a dedicated USB cable, if you can disassemble the connector, I found it much easier to open the charger itself to short the pins.
i also have a gigabyte mobo that has this feature but i havent gotten around to test it out yet. I dont think it would work because the feature is software based and will only bump up the voltage if the program detects an iphone connecting to your computer. Gigabyte doesnt want to be liable if they bump up voltage on every device you plug in and fry something.
btw I have tried charging my n1 from my computer and its extremely slow. started charging at around 5pm on sunday and at 11pm it went from about 23%-97% lol.
Yes, USB charging is very slow. It's actually good for the battery, though.
Maybe someone with some know how can look at the driver files for this 3x tech and see how it checks if its an Apple device. Then fool the check and presto!
Shame I don't know how to do any of this
There is a simple hardware (don't worry, it's on the cable) mod for faster charging; however, make sure the phone has good air vent (it means NO CASE when charging).
1. modify your microUSB cable, disconnect the data connector the A (host) plug, then shorten the data connector to the B plug. (This can charge N900 properly, and speed up n1 charging).
2. modify your powered (with AC adapter plugged) USB hub. Simply shorten the #2 and 3 connectors on USB jack. Make sure you cut the copper strip going to the chip or malfunction may occur.
These modification can greatly speed up the charging, but phone will produce a lot of heat (that's why you must have the phone "naked").
I don't understand this. If the phone + battery are capable of being charged at 1000 mAh from the wall charger then why need extra cooling when asking for 1000 mAh from a PC USB socket?
Mine's still defo getting only 500 mAh from the PC USB despite it being able to give up to 2700 mAh for iPad!!! All I want is my 100 mAh charge.
Because what he suggests isn't a proper charging but rather removal of slot power control, and will damage the battery / phone, if succeeds.
Proper charging at 1000mAh requires pulsing voltage - his hack doesn't provide that. Your MB does, but it requires SW intervention to turn it on.
So can someone brew the intervention ?
martinl1030 said:
i also have a gigabyte mobo that has this feature but i havent gotten around to test it out yet. I dont think it would work because the feature is software based and will only bump up the voltage if the program detects an iphone connecting to your computer. Gigabyte doesnt want to be liable if they bump up voltage on every device you plug in and fry something.
btw I have tried charging my n1 from my computer and its extremely slow. started charging at around 5pm on sunday and at 11pm it went from about 23%-97% lol.
Click to expand...
Click to collapse
They are not doing anything to the voltage, simply allowing more current to pass.
And as said in this thread, any typical data USB cable will charge very slowly. And most standard USB ports charge well less than the max specced 500mAh, in fact my subnote at work I found charged my old phone at around 150mah one time when I was dead and needed to top off and it's all I had available.
i'm not sure of the pinout on the micro USB port but i'm pretty sure that that the Mini USB-B port that was used on phones like the G1 used shorting the -Data pin to the unused 5th pin (actually pin 4 on the connector pinout) to activate AC charge mode. some devices actually require a resister of a certain value to be placed across them to work(i know older motorola phones did like IDEN's)
one thing people often forget but should not forget is that current is drawn from the device using power. its not forced on the device. voltage is forced on a device and while a variance is usually ok for devices depending on how they were designed generally its not a good idea to exceed +1.5v on any low power DC device. 120V AC devices are designed to actually work in a much wider range like 100-130V but thats because of the power supply/nature of AC power. it always varies and in japan they use 100v 60hz AC so many electronics power supplies are designed to work in the full range to save costs and only have to make 1 unit for all (same deal with 220-240 switches on PC power supplies)
the reason why you don't want to do this mod is you could damage you PC's motherboard by pulling too much current from its circuits. USB spec is 500ma. performing this type of mod on a power adapter (car or AC) that does not get recognized as an AC charger by the phone is a safer way to go. worst case senario is you break the charger (unless you mess up on the pinout then you could damage you phone too though)

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

Galaxy Tab charging issue + solution

Hey guys - I've been dealing with a Tab charging issue for a few days, and finally solved it... but I thought I'd post the problem and solution here in case it can save someone else a load of frustration if they run into the same problem.
From what I've read, we know that the Tab only draws .5A power from a USB socket, but that it draws ~2A from the wall, and that it knows the difference by testing for a short on the TX/RX USB data wires. (Correct me if I'm wrong on the details, but that's the general impression I've gotten.) We also know that the iPhone/iPad/iPod uses a pair of resistors instead (per the USB spec) to determine the current-delivery capability of the source. (I'm no EE, so I'm a little fuzzy on how that works from a technical perspective.)
So to set the stage: I had brought the USB cable for my Tab with me, but had neglected to grab the USB->outlet adapter for the mains. Similarly, a friend who was on vacation with us had forgotten the charging cable for his iPhone. Thinking I was killing two birds with one stone, I bought an aftermarket USB charging cable for the iPhone which had a separate USB->outlet adapter. His iPhone charged swimmingly, and when I charged my Tab overnight (screen off, starting at ~89% charge) using my cable and the aftermarket adapter, it worked flawlessly. No problem, great solution, or so it seemed...
...until I got home. Suddenly, my Tab wouldn't do more than a trickle charge - the same charge it gets when connected to the USB port on my laptop. (I could tell this was the case because of the small red 'x' next to the charging symbol in the battery icon - which I hadn't noticed while on vacation.) A 2.5-hour car trip using Navigator (screen on the whole time), even with the car charger connected, killed the battery completely. No matter what I did - shutting down apps, rebooting the device, resetting every option I could find - I could not get a fast charge to happen. Even leaving the device plugged in overnight resulted in *less* charge than what I started with if I didn't turn the screen off. I called T-mobile, talked to Samsung tech support twice... and all they could offer was to have me send the Tab back for replacement.
I was at a loss. I nearly did a hard reset in frustration, thinking I had screwed something up royally.
Then I saw the resistors in the pictures in this post:
http://forum.xda-developers.com/showthread.php?t=845844&page=3
and something clicked. I had been assuming that the *cables* were the difference between the iPhone and Tab chargers... but there isn't enough room for resistors in the cables! (Well technically, there is, but regardless...) The resistors must live somewhere else... and, I reasoned, that somewhere must be inside the USB->outlet adapter. So I pulled out the 'proper' Samsung adapter, plugged in the Tab, and voilà... a perfect fast charge.
So this is why the Tab won't charge with an iPod (or Sony-Ericsson, as it turns out) mains USB adapter OR USB-port car charger: the circuitry to let the device know it's capable of a full 2A delivery doesn't live in the Samsung cables; it's only present in the adapter. If that's not there, the device thinks it's connected via USB (and will, in fact, say "USB Connected" every time the charger is plugged in) and won't charge more than a trickle.
So that's my story, and hopefully it can save someone else some pain and frustration. Thanks for giving me the floor.
mattcelt said:
Hey guys - I've been dealing with a Tab charging issue for a few days, and finally solved it... but I thought I'd post the problem and solution here in case it can save someone else a load of frustration if they run into the same problem.
From what I've read, we know that the Tab only draws .5A power from a USB socket, but that it draws ~2A from the wall, and that it knows the difference by testing for a short on the TX/RX USB data wires. (Correct me if I'm wrong on the details, but that's the general impression I've gotten.) We also know that the iPhone/iPad/iPod uses a pair of resistors instead (per the USB spec) to determine the current-delivery capability of the source. (I'm no EE, so I'm a little fuzzy on how that works from a technical perspective.)
So to set the stage: I had brought the USB cable for my Tab with me, but had neglected to grab the USB->outlet adapter for the mains. Similarly, a friend who was on vacation with us had forgotten the charging cable for his iPhone. Thinking I was killing two birds with one stone, I bought an aftermarket USB charging cable for the iPhone which had a separate USB->outlet adapter. His iPhone charged swimmingly, and when I charged my Tab overnight (screen off, starting at ~89% charge) using my cable and the aftermarket adapter, it worked flawlessly. No problem, great solution, or so it seemed...
...until I got home. Suddenly, my Tab wouldn't do more than a trickle charge - the same charge it gets when connected to the USB port on my laptop. (I could tell this was the case because of the small red 'x' next to the charging symbol in the battery icon - which I hadn't noticed while on vacation.) A 2.5-hour car trip using Navigator (screen on the whole time), even with the car charger connected, killed the battery completely. No matter what I did - shutting down apps, rebooting the device, resetting every option I could find - I could not get a fast charge to happen. Even leaving the device plugged in overnight resulted in *less* charge than what I started with if I didn't turn the screen off. I called T-mobile, talked to Samsung tech support twice... and all they could offer was to have me send the Tab back for replacement.
I was at a loss. I nearly did a hard reset in frustration, thinking I had screwed something up royally.
Then I saw the resistors in the pictures in this post:
http://forum.xda-developers.com/showthread.php?t=845844&page=3
and something clicked. I had been assuming that the *cables* were the difference between the iPhone and Tab chargers... but there isn't enough room for resistors in the cables! (Well technically, there is, but regardless...) The resistors must live somewhere else... and, I reasoned, that somewhere must be inside the USB->outlet adapter. So I pulled out the 'proper' Samsung adapter, plugged in the Tab, and voilà... a perfect fast charge.
So this is why the Tab won't charge with an iPod (or Sony-Ericsson, as it turns out) mains USB adapter OR USB-port car charger: the circuitry to let the device know it's capable of a full 2A delivery doesn't live in the Samsung cables; it's only present in the adapter. If that's not there, the device thinks it's connected via USB (and will, in fact, say "USB Connected" every time the charger is plugged in) and won't charge more than a trickle.
So that's my story, and hopefully it can save someone else some pain and frustration. Thanks for giving me the floor.
Click to expand...
Click to collapse
I've recently seen (somewhere) a usb pigtail cable that shorts the pins to make the tab (or any other usb chargable phone) think it's hooked up to a wall charger, rather than a trickle charging usb port.... I need to find that again and just order a few to have in my various cable bags.
If you do find it again, please post it here. Definitely something I'd like in my bag of tricks as well.
Just as an FYI, the 2A charger that came with my Nook Color charges the Tab just fine from mains, even indicates charging. Makes sense, since both devices have a 4000mAH battery.
It's also a nicer unit for travel, it's nicely rounded, the prongs fold into the body of the charger, and you can pick it up from Barnes and Nobles stores just about anywhere in the US. Still doesn't solve the Tab cable issue though.
Croak said:
Still doesn't solve the Tab cable issue though.
Click to expand...
Click to collapse
I'm planning on hacking apart a spare Tab cable so that it goes to a female microUSB; no more multiple cable types then. The stock Tab cable doesn't appear to have more than 6 pins, of which I'm sure a few are grounds.
Someone recently posted a link to the first cheap 3rd-party cables:
http://www.dealextreme.com/details.dx/sku.51931
Get those with a 6' USB extension cable and the Nook charger, and that may be a winning combination. I ordered four the the charging cables yesterday, and I'll try to remember to post whether or not they work out well.
Resonance, what are you planning on using for a car charger, if any? I really like the Navigator app, but it's just not practical if I can't keep the Tab charged while using it.
Does anyone know if there are any USB->12v adapters that have the right circuitry for the Samsung? For that matter, do any other devices use the same amperage detection setup the Tab does? It would be good to know what components are cross-compatible.
Thanks for the info.
How about a list of chargers that work fine on the GTab.
1. Garminfone charger (1amp - works great and I use it as my primary charger)
mattcelt said:
Resonance, what are you planning on using for a car charger, if any? I really like the Navigator app, but it's just not practical if I can't keep the Tab charged while using it.
Click to expand...
Click to collapse
A 12V inverter, attached to the standard wall charger. :/
I bought the Duragadget 12V->USB charger, since it was advertised specifically as a 2A charger for the Galaxy Tab, but it DOES NOT work as advertised (the Tab treats it like a any other low-current USB port, and even offers to mount mass storage, heh).
Using the inverter and the wall charger worked just fine, though it was a bit clunky and unstable (on mine, the prongs aren't tightly gripped, so it bends out of place easily).
Does anyone know if there are any USB->12v adapters that have the right circuitry for the Samsung? For that matter, do any other devices use the same amperage detection setup the Tab does? It would be good to know what components are cross-compatible.
Click to expand...
Click to collapse
I'd been contemplating giving the Duragadget charger with integrated cable a try, but having been burned once by Duragadget, I'm a bit hesitant to do so.
ResonanceZero said:
Someone recently posted a link to the first cheap 3rd-party cables:
http://www.dealextreme.com/details.dx/sku.51931
Get those with a 6' USB extension cable and the Nook charger, and that may be a winning combination. I ordered four the the charging cables yesterday, and I'll try to remember to post whether or not they work out well.
Click to expand...
Click to collapse
OMG...I bought a charger cable from amazon SOLD BY AMAZON marketed as OEM samsung charger and I got the same one in the deal extreme page. WTF...paid $12 for it too.
ResonanceZero said:
A 12V inverter, attached to the standard wall charger. :/
I bought the Duragadget 12V->USB charger, since it was advertised specifically as a 2A charger for the Galaxy Tab, but it DOES NOT work as advertised (the Tab treats it like a any other low-current USB port, and even offers to mount mass storage, heh).
Using the inverter and the wall charger worked just fine, though it was a bit clunky and unstable (on mine, the prongs aren't tightly gripped, so it bends out of place easily).
I'd been contemplating giving the Duragadget charger with integrated cable a try, but having been burned once by Duragadget, I'm a bit hesitant to do so.
Click to expand...
Click to collapse
looks like that car charger is the same as the one you bought with a USB cable included.
nacron said:
looks like that car charger is the same as the one you bought with a USB cable included.
Click to expand...
Click to collapse
Good eyes. I thought it was a different unit with an integrated cable.
Has anyone found a functioning 12v charger?
yes, the verizon store has a 12v charger for the galaxy tab, but that was the only place I was able to find one... other than online.
Hi,
Can anyone else confirm that the Nook charger works for the Tab?
I've tried other high current (2.0+ amp) chargers. Some designed for the ipad and some not, and I always get the trickle charge icon and it's treated as a computer USB connection (Mass storage device options, etc).
How much was the Verizon charger?
Thanks!
stock wall charger works for me.
knowthenazz said:
Hi,
Can anyone else confirm that the Nook charger works for the Tab?
I've tried other high current (2.0+ amp) chargers. Some designed for the ipad and some not, and I always get the trickle charge icon and it's treated as a computer USB connection (Mass storage device options, etc).
How much was the Verizon charger?
Thanks!
Click to expand...
Click to collapse
Google the gobatt 2 charger. It comes with a usb adapter that charges the tab on any charger.
texasreb said:
Google the gobatt 2 charger. It comes with a usb adapter that charges the tab on any charger.
Click to expand...
Click to collapse
Hi,
Thanks for the tip. I can't find much information about the Scosche GoBatt 2 charger, or the adapter that comes with it. Today I tried other Scosche chargers, including their iPad charger, and it didn't seem to work.
Can you give some more details on the adapter that comes with the GoBatt 2?
Thanks!
Got this travel adapter by ZipKord with 2 - 1 amp outlets. Works with the OEM cord and also the Gomadic tip made for the Galaxy Tab. Just need to be careful it's not the older version that only has the lower power outlets. Cheapest I could find was $13+, so if it's less, it's the lower power. With the Gomadic tip and reractable cord, it says it's charging.
EVO 4G 9292 - Travel Adapter By ZipKord
Also this Scosche battery pack seems like it would work. Has 2 - 1 amp USB ports. I ordered one and should get it tomorrow.
Scosche IPDBAT2 Portable Back Up Battery for iPad and iPod
Oops - can't do links. Just search in Amazon. It's where I got both.
Gomadic cord and tips from Gomadic. Love losing the excess clutter (cords).
galaxy tab 7 charging while turned on
can someone explain well how to build the adaptor for charge galaxy tab 7 while it turned on?
is it possible to have a scheme with picture and some photos which describe the work to do?
thanks. and excuse me for bad english.
mattcelt said:
Hey guys - I've been dealing with a Tab charging issue for a few days, and finally solved it... but I thought I'd post the problem and solution here in case it can save someone else a load of frustration if they run into the same problem.
From what I've read, we know that the Tab only draws .5A power from a USB socket, but that it draws ~2A from the wall, and that it knows the difference by testing for a short on the TX/RX USB data wires. (Correct me if I'm wrong on the details, but that's the general impression I've gotten.) We also know that the iPhone/iPad/iPod uses a pair of resistors instead (per the USB spec) to determine the current-delivery capability of the source. (I'm no EE, so I'm a little fuzzy on how that works from a technical perspective.)
So to set the stage: I had brought the USB cable for my Tab with me, but had neglected to grab the USB->outlet adapter for the mains. Similarly, a friend who was on vacation with us had forgotten the charging cable for his iPhone. Thinking I was killing two birds with one stone, I bought an aftermarket USB charging cable for the iPhone which had a separate USB->outlet adapter. His iPhone charged swimmingly, and when I charged my Tab overnight (screen off, starting at ~89% charge) using my cable and the aftermarket adapter, it worked flawlessly. No problem, great solution, or so it seemed...
...until I got home. Suddenly, my Tab wouldn't do more than a trickle charge - the same charge it gets when connected to the USB port on my laptop. (I could tell this was the case because of the small red 'x' next to the charging symbol in the battery icon - which I hadn't noticed while on vacation.) A 2.5-hour car trip using Navigator (screen on the whole time), even with the car charger connected, killed the battery completely. No matter what I did - shutting down apps, rebooting the device, resetting every option I could find - I could not get a fast charge to happen. Even leaving the device plugged in overnight resulted in *less* charge than what I started with if I didn't turn the screen off. I called T-mobile, talked to Samsung tech support twice... and all they could offer was to have me send the Tab back for replacement.
I was at a loss. I nearly did a hard reset in frustration, thinking I had screwed something up royally.
Then I saw the resistors in the pictures in this post:
http://forum.xda-developers.com/showthread.php?t=845844&page=3
and something clicked. I had been assuming that the *cables* were the difference between the iPhone and Tab chargers... but there isn't enough room for resistors in the cables! (Well technically, there is, but regardless...) The resistors must live somewhere else... and, I reasoned, that somewhere must be inside the USB->outlet adapter. So I pulled out the 'proper' Samsung adapter, plugged in the Tab, and voilà... a perfect fast charge.
So this is why the Tab won't charge with an iPod (or Sony-Ericsson, as it turns out) mains USB adapter OR USB-port car charger: the circuitry to let the device know it's capable of a full 2A delivery doesn't live in the Samsung cables; it's only present in the adapter. If that's not there, the device thinks it's connected via USB (and will, in fact, say "USB Connected" every time the charger is plugged in) and won't charge more than a trickle.
So that's my story, and hopefully it can save someone else some pain and frustration. Thanks for giving me the floor.
Click to expand...
Click to collapse
potential solution
found this on youtube, looks like it has great potential:
forum won't let me post url links, but this is the video code in you tube. We're all geeks here (I think) so you know where this goes :
=uPc-ZA3t5aY
hope it helps!

Impossible to charge sg2 in car

Hi all, just came 3 days ago from an htc hd2, and so far I am more than happy with it.
I have only one complaint and maybe you guys will help me sharing your experience : I can't charge this phone in my car while using gps.
It seems that the power adapter is not powerful enough to charge the phone screen on.
The car charger has a 5v 1000ma output, more than the regular wall charger provided by Samsung and it was working well before with my HD2 so I have no clue about this problem.
Did you experience that issue too, else can you share what car charger do you use?
try to buy new standard car charger with micro plug.. 13 eur and you will be saved..
Sent from my GT-I9100 using XDA App
Charger doesn't matter unless the phone is dropping into USB charging mode - phone limits to around 600-650 mA by default.
Custom kernels can bump this limit up for I9100 users. I777 users are screwed - we've got a crippled charger chip.
I had the same problem, I used the samsung one, useless, so I used my iPad charger, which is 2A, and charges the iPad quick, still useless. We drove from Bathurst NSW, down to Melbourne, about 10 hour drive, plugged in all the way using GPS, and about an hour from home, the connect to charger warning came on!! So once I stopped GPS, it started taking charge. Looks like when the phone is in use, it draws more then it takes charge, plus I read somewhere on here the phone is limited on the charge it takes, so using the 2A does nothing different then the stock 500mA charger.
I always had this problem with my Nexus One, although they are different phones, the problem is the same, uses more power then it can recharge in USB mode.
After trying 3 or 4 different charges I remember that I found one ultra-cheap 'made in taiwan' from a street seller that worked very well.... so it's kind of a lucky shot!
good luck!
Im using a genuine Samsung SGS2 charger and I can charge and run Sygic just fine. I started my journey with 80% and 40mins later I was up to 91% when I stopped and got out. (not in aeroplane mode..)
Very interesting feedbacks... So that confirm that is clearly not a matter of output amperage power.
It is now the same problem on the galaxy tab 10.1, for quickly charge this tab you need the Samsung compatible usb adapter.
It can be likely with a tab bringing a proprietary plug, but I didn't thought it will be the same with a Samsung phone bringing a regular micro usb plug. Quite frustrating and disappointing!
I will search around a micro plug car charger as suggested by redzion, but actually I don't clearly see the difference with my usb charger + a micro usb cable.
Double post, sorry.
If I use the usb cable from my cd player I have the same problem but if I use the official Samsung car charger Ithe only problem I have is the phone getting stupid hot
Sent from my GT-I9100 using xda premium
Oh Samsung, when you will understand?!
Samsung DOES follow the USB charging standard - it goes to its highest current setting when a charger that follows the standard is connected.
Note that iPad/iPhone chargers do NOT follow the standard - Samsungs will treat these as USB hosts and limit to 450 mA instead of 600-650.
Modified kernels can increase both of these values on I9100s.
The only thing Samsung really did **** up is counting screen/CPU current usage against the charge current limits - that's just stupid.
So the charger has smarts. On the i9000 factory chargers, the data pins were bridged. Bridging these pins manually on a USB cable when connecting to a USB source (such as a PC) enabled full current charging. You can see this in Settings -> About; it will say either USB or AC charging.
Do you think this is the case with the i9100?
I don't condone testing this theory on your i9100. Increasing the max current via custom ROM may be a safer solution.
I had the same problem. Two things fixed it for me:
1) I bought this charger: Sony Ericsson AN300 Micro USB 10€
2) I am using a custom kernel now
Any charger that is rated at 1000mA or more (per port) will do just fine. The problem is the cable - you need a quality microUSB cable, or it won't provide all the juice you need. I had the same issue, and I swapped three chargers until I found the real culprit.
Try with the charger you have now and the mUSB cable that was in the phone box - it should work well with that one.
I just press the power button to turn the screen off. when i need the sat nav i press the power and it still tracks you so there is no delay. With the screen off it does charge.
same problem
Duffman19 said:
I just press the power button to turn the screen off. when i need the sat nav i press the power and it still tracks you so there is no delay. With the screen off it does charge.
Click to expand...
Click to collapse
You are right, but even if it is better than nothing the charging time is still a big problem.
Yesterday I drove for at least 40mn phone off. Arrived to destination, I turn the device on: it charged only from 0 to 5%
I would like to test the mariusi theory concerning the Samsung micro usb cable, unfortunately on my SgsII box I just have a wall charger, no a microusb-usb cable.
Entropy512 said:
Samsung DOES follow the USB charging standard - it goes to its highest current setting when a charger that follows the standard is connected.
Click to expand...
Click to collapse
Is there a way to know before buying if the charger respect this charging standard?
I have some cheap usb chargers here and no one is a fast as the one provided by Samsung.
Entropy512 said:
The only thing Samsung really did **** up is counting screen/CPU current usage against the charge current limits - that's just stupid.
Click to expand...
Click to collapse
Maybe for safety purpose? Gps phones can become very hot behind the car glass.
Samsung are trying to "encourage" you to buy only their official accessories. To do this they've wired something differently in their chargers and cables. This "problem" exists on the Galaxy Tab too and can be solved with this adapter...
http://www.ebay.co.uk/itm/USB-car-w...ccessories&hash=item2c5c07736b#ht_3084wt_1163
It's cheap and turns a trickle charge into a full charge. I don't know the specifics of what they've done, but their USB charging just isn't the same as most others manufacturers.
Archer said:
It's cheap and turns a trickle charge into a full charge. I don't know the specifics of what they've done, but their USB charging just isn't the same as most others manufacturers.
Click to expand...
Click to collapse
Great find.
Pretty sure it just bridges the data pins.

[Q] original cable not charging fast enough

I just realized my original cable doesn't charge my phone fast enough and I drain battery while using it. I swapped for a Motorola micro usb, and it works.
I downloaded an app to show mA rate, and with original cable it goes at about 360 or 450 mA. When I use Motorola cable it goes to 1900mA and proceeds to raise battery %.
What can cause this? The plug looked little dusty, I stuck a twist tie in and out (like on bread bad) and tried to clean it, but there's no difference.
Also there's no pin 4 on my cable, the ID pin I think. That seemed to be common for Samsung, so guys, what do you think caused cable to go bad, or am I missing something?
Also I use BlackBerry charger it says 800mA, this will charge it.
Thank you.
Could have just gone bad. Batteries go and all the time. I just had o swap out my sisters amdnmine for new ones because they wouldn't hold a charge for more than 6-7 hours. So its possible you just had a faulty one. Btw the phone is meantnto charge slowly. The faster your battery charges usually means the battery is giving out. But in your case you found out it was the data cable.
Could u tell me which app you used to show mA charge rate.
farookh said:
Could u tell me which app you used to show mA charge rate.
Click to expand...
Click to collapse
Yeah sure.
Galaxy charging current lite
https://play.google.com/store/apps/details?id=com.abmantis.galaxychargingcurrent.free
Its your wall mount. Try plugging the original USB into the moto box. It should charge fine. If not try the obvious (original box to moto USB)
Happened to me on my s3 and my s4. Sucks.. i know..
Daisflaque said:
Its your wall mount. Try plugging the original USB into the moto box. It should charge fine. If not try the obvious (original box to moto USB)
Happened to me on my s3 and my s4. Sucks.. i know..
Click to expand...
Click to collapse
No pretty sure it's the cable. Used cable on 2A nexus charger, and it only did 300 mA.. I wonder where I can buy a good 4 or 5 foot usb cable for not too much money? The default usb cable length (3ft) is usually too short to reach the outlet for me. =(
I just googled this.. cheap 6ft samsung micro usb.. great prices from local places like walmart and amazon.
Although you might wanna add 2000mah. Lol
300Ma means your USB cable has no Power wire and you are just getting power from Data wires
460Ma is what you would get from a Data USB port
1A is what you get with a good USB cable and Charging Data port
1.2-1.9A is what you get with a good USB cable and Wall/car charger that can provide 2.1A.
good USB cable= 2core for power with 24AWG wire size and 2 Data wires at 28AWG.
Not longer than 6feet

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