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!
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.