Database Users

Charging without Samsung AC Adapter?

I went out of town this week and made sure to grab my USB cable, but left the AC adapter at home figuring I'd just charge off my laptop via usb. Apparently not... I also tried plugging the USB cord into my iPhone AC/usb adapter with no luck. The only thing I've found is that when you turn off the Tab and connect to one of these devices, a green battery indicator will pop up showing that it is charging. Well, after about 16 hours, it made it from 15% all the way up to 48%. Does anyone know any way around turning it off to charge or why it is barely charging when it is off?

Jaydawgx7 said:
I went out of town this week and made sure to grab my USB cable, but left the AC adapter at home figuring I'd just charge off my laptop via usb. Apparently not... I also tried plugging the USB cord into my iPhone AC/usb adapter with no luck. The only thing I've found is that when you turn off the Tab and connect to one of these devices, a green battery indicator will pop up showing that it is charging. Well, after about 16 hours, it made it from 15% all the way up to 48%. Does anyone know any way around turning it off to charge or why it is barely charging when it is off?
Click to expand...
Click to collapse
Well seeing as it has a 7000mAh battery, just about any run-of-the-mill USB charger isn't going to cut it. The amperage would have higher as well. Now i would hazard that an iPad charger (10 watts) would probably work just fine vs an iPod charger.
Your laptop's USB port isn't providing enough juice to charge fully. With the screen off it will only trickle charge and very slowly at that.

You'll need at least 5 Volt 2 Amp chargers.
You can also try this:
http://forum.xda-developers.com/showpost.php?p=14890063&postcount=16
Or this:
http://cgi.ebay.com/190522553195?ru...ee-All-Categories&_fvi=1&_rdc=1#ht_3085wt_905
I've ordered both last week but neither have arrived yet. I'll report back.

You need a 5vdc supply that will provide 2A. 10W, not 5w as the previous post said. That adapter on ebay won't help the charge, it just disconnects the data line so it does not change its mode when connected to a computer. There are a lot of power supplies that will work and even more that won't, just made sure it supplies 2a. If you want to charge off your laptop then you will want a Y adapter similar to what is on usb powered hard drives but even then you will need to use 2 usb 2.0 or 3.0 ports and will provably only get 1a out.
Sent from my GT-P7510 using XDA Premium App

Charging using USB

Hello
as we know, we cannot charge our Transformer using USB.
Thats a pitty as I bought a Solat Charger (expensive one) which can charge USB-Devices.
Now does anyone know how we can fix this? I thought about buying a second cable and changing some connectors? Power is power, it has to work somehow...
any ideas?
thanks
Dominik
Sent from my LG-E900 using Board Express

You've got to somehow mod it to give us 15v, buy a usb 3.0 female and change some pin layouts.

DominikReber said:
Hello
as we know, we cannot charge our Transformer using USB.
Thats a pitty as I bought a Solat Charger (expensive one) which can charge USB-Devices.
Now does anyone know how we can fix this? I thought about buying a second cable and changing some connectors? Power is power, it has to work somehow...
any ideas?
thanks
Dominik
Sent from my LG-E900 using Board Express
Click to expand...
Click to collapse
It depends how fast you want to charge. I plugged the ASUS cable into an apple charger last night. I then connected it to the tablet and shut the tablet down. When I started charging the tablet was at 72%, when I got up 7.5 hours later, it was up to 93%. So it wouldn't be enough to charge it from nearly empty, but it might be enough to top up the charge after using the tab for a couple of hours. This is with the ASUS cable and no modification to the charger at all.

According to the Tip sheet that came with my TF, USB on a computer can charge it, but only when the TF is in sleep mode (screen off) or powered off.
Have you tried the solat charger to see if it does indeed charge the TF when the screen is off?

Most solat chargers have a 12v plug to power car cigarette jack devices. Connect this to a female usb plug and you can charge your tranformer and dock.

Search for the Charging thread started by Devcake. There is an extensive discussion on the charging requirements of the TF and charging options. Also the pinout and function for the connector. It is NOT true USB 3.0. It just happens to use that connector and some of the conductors.

Won´t charge unless it's off

Hi,
Is there anything I have to do for the GT 7.7 to charge while it's on? I´ve notice that it will only charge when it's off.
I've tested charging via usb and via outlet (2 different cables). I´m using the rom that came with it (as a matter of fact I haven't even rooted the tablet).
Any thoughts?

Which charger are you using? Seems you need to use a correct rated charger (ie the one that came with it) for it. Normal usb power hasn't got sufficient power.
You can trick it into using usb but you need an adapter from eBay
Sent from my HTC Desire S using Tapatalk 2

I´m using the charger that came with it. I've tried charging connected to my laptop and I've tried connected to the outlet (at least this last one should work).

rawfa said:
I´m using the charger that came with it. I've tried charging connected to my laptop and I've tried connected to the outlet (at least this last one should work).
Click to expand...
Click to collapse
Charging using usb port has not enough current (500mA only), unless your computer has a high current output usb port (1A - not many have).
The supplied charger is rated at 2A if I'm not mistaken, and take around 3 hrs to fully charge from empty, maybe more...

skycruzer said:
Charging using usb port has not enough current (500mA only), unless your computer has a high current output usb port (1A - not many have).
The supplied charger is rated at 2A if I'm not mistaken, and take around 3 hrs to fully charge from empty, maybe more...
Click to expand...
Click to collapse
It DOES charge, but only when it´s turned off.

It will charge when off if you are using the USB cable
If you are using the cable that plugs into a powerpoint then it'll charge when ever.

rawfa said:
It DOES charge, but only when it´s turned off.
Click to expand...
Click to collapse
Has Samsung Kies installed on that laptop your USB was plugging into?

Proprietary charger?

I've read that the Nexus 7 charges via regular micro USB (no proprietary port or cable) and that the charger is a 2A charger. Has anyone figured out the proprietary aspects of the charger that signal to the Nexus 7 that it's connected to the charger and that it's ok to draw 2A?

Bump.

I think it just dumps 2A into all the devices. 99% of USB devices have resistors in them to limit the current
Sent from my Nexus 7 using xda app-developers app

It needs a 2amp charger... 1amp will keep it on indefinitely but wont charge... with less than 1amp (say keyboard USB port) the battery will lowly drain on while the power indicator shows charging and eventually the screen will go nuts and the device will crash/shutoff
Sent from my Nexus 7 using xda premium

pixelchemist said:
It needs a 2amp charger... 1amp will keep it on indefinitely but wont charge... with less than 1amp (say keyboard USB port) the battery will lowly drain on while the power indicator shows charging and eventually the screen will go nuts and the device will crash/shutoff
Sent from my Nexus 7 using xda premium
Click to expand...
Click to collapse
Don't think you are accurate. If computer usb can charge the device (0.5A from usb port on computer), any charger can charge n7, albeit charger with lower current will take longer to fully charge the device. Tried 1A charger on N7, no problem.
Sent from my Galaxy Nexus using xda premium

There is the standard CYA in the manual to only use the cable and charger supplied with the unit. If it is fully powered down, pretty much any microUSB will charge it... eventually. That's not necessarily the best thing for the battery. If the power is under 2A as suggested, depending upon what you're doing with the tablet, it may just be enough to keep it running, or, could actually drop to zero even in use. (This happened with my Nook Color, for example). YMMV, but on the stock charger, the recharge is pretty quick. My only quibble is that there is no notification light to alert you to charge completion, or other notifications you might get (gMail, texts through Google voice, etc.).

tylerwatt12 said:
I think it just dumps 2A into all the devices. 99% of USB devices have resistors in them to limit the current
Sent from my Nexus 7 using xda app-developers app
Click to expand...
Click to collapse
This is incorrect. It's not up to the charger to push 2A, but rather up to the device to pull 2A through signaling of specific voltages on the data lines. For example, if you were to normally plug any tablet besides an iPad into an iPad charger (2.1A), the most you can expect to pull is 1A because the tablet doesn't know that it's connected to a 2.1A charger. The internals of the iPad charger will only tell an iPad that it's connected to a 2.1A charger. In order to charge at 2A with another tablet on the iPad charger, you need to do something like this example with the Galaxy Tab:
http://forum.xda-developers.com/showthread.php?t=845844
Or buy a pre-made adapter:
http://www.dealextreme.com/p/usb-ma...ung-galaxy-tab-p7500-more-black-127843?item=6
So the Nexus 7 charger must have something going on to tell the Nexus 7 that it's connected to the right charger because it can't try to pull 2A from every USB port that it's plugged into (some computers will actually shut down if something tries to draw too much power through the USB ports).
bitbearmi said:
My only quibble is that there is no notification light to alert you to charge completion, or other notifications you might get (gMail, texts through Google voice, etc.).
Click to expand...
Click to collapse
NoLED can alert you about notifications by flashing icons corresponding to the notification on the screen. It turns the screen on, which will obviously drain your battery, but there's a setting to disable turning on the screen when the proximity sensor is "close", so what you can do is put it screen-side down when it's off the charger to keep it from turning on the screen. It's not as elegant as a notification LED or backlight notifications (which is what I'm used to), but it's better than nothing.

Something I'd like to add not sure if its true but it was an explanation relating to this I saw when shopping around for an in car charger and makes some sense.
Android will reduce the power it pulls from a USB port if it detects it as a data port as opposed to an AC connection in order to conform to the official USB specs.
Apparently some chargers are wired incorrectly (data pins should be cross connected in chargers for it to be recognised as a charger if I remember the description) and will be picked up as a data port. Some devices will just use as much power as possible on data ports but ones that conform to the specs will take only the amperage outlined in USB specs.
Like I said its just something I remember don;t shout at me if I'm talking mince.
Sent from my Transformer while the N7 is lost in the Play Store Black Hole.
16gb N7 UK ordered 3rd July.

It's mildly related to proper charging. Basically, for any tablet, there are three charging states. The first is USB mode, where the data pins aren't shorted (as if the device was connected to a computer's USB port), which draws a maximum of 0.5A. The second is AC mode, where the data pins are shorted, which draws a maximum of 1A. The third mode is what I'll call high speed AC, and this is the mode we're after. Not only are the data pins shorted, but voltage is being applied to the data pins in a specific way to each device family. When the device detects this mode, it'll think that it's connected to its own charger and try to draw up to 2A.
Every device family has its own required voltages on the data lines, and by families, I mean products that have interchangeable chargers (like iPads, Galaxy Tabs, Transformers, etc) so if we can figure out what the Nexus 7 needs, then we can use any 2A charger with it (like using an iPad car charger). I just realized that others have said that they were able to charge at high speed with their Transformer charger, so I suspect that we can refer to Transformer charging adapters to get it working.

I haven't taken apart my Nexus 7 charger to see what's inside mainly because I've only got the one...
but I did verify that the D+ and D- pins on the USB are shorted, but there is no discernable voltage being applied to either.

So I set up my meter (and sacrificed my really short asus OEM charging cable) to measure the current draw while charging... this is what I found:
OEM charging cable appears to be just a regular old USB cable, unless there is something happening in the micro usb end, which I really doubt.. but I don't have any adapter to check if this is the case.
When D- and D+ are floating and not shorted together, the Nexus 7 draws ~1A but the charging indicator does not come on.
When D- and D+ are shorted together the Nexus 7 draws ~1A and the charging indicator does come on.
I could not get the Nexus 7 to draw 2A. Maybe I broke something
-J

Thanks for making the sacrifice. I guess more testing is needed.

I think the theory that it doesn't draw more than 1.0a may be correct. But it is still finicky about the charger. I have a palm OEM charger with palm cable and it doesn't charge the N7. I have a Nokia 1.2a charger and Blackberry 1.8a charger and they both seem to charge near the same rate, as fast as the Asus OEM charger.

Just as another data point, I tried connecting my n7 to the ipad ac charger, which is a 2A charger. It doesn't charge at all against the ipad charger.

kmandel said:
Just as another data point, I tried connecting my n7 to the ipad ac charger, which is a 2A charger. It doesn't charge at all against the ipad charger.
Click to expand...
Click to collapse
Anybody with the N7 that charges on the iPad charger? If so, I want to return it.
Domi

Limited charging options
dmalovic said:
Anybody with the N7 that charges on the iPad charger? If so, I want to return it.
Domi
Click to expand...
Click to collapse
It won't charge off an OEM iPad charger, just checked. It also won't charge off a Monoprice 3x outlet with 2x 2.1a usb directly connected to the usb ports or a 2.1a backup battery. Damn device is really picky about the source.
It will charge off my Touchpad and Vizio tablet charger.
I'm really bummed out it won't charge off the monoprice 3x outlets 2x usb since I bought a bunch of them when they were on sale and put them through out my house.

kkeo said:
It won't charge off an OEM iPad charger, just checked. It also won't charge off a Monoprice 3x outlet with 2x 2.1a usb directly connected to the usb ports or a 2.1a backup battery. Damn device is really picky about the source.
It will charge off my Touchpad and Vizio tablet charger.
I'm really bummed out it won't charge off the monoprice 3x outlets 2x usb since I bought a bunch of them when they were on sale and put them through out my house.
Click to expand...
Click to collapse
Same here.. just tried an ipad charger and it didn't work.. this is the oem ipad 3 charger. Also tried ipad 1 charger (should be same thing) didn't work.. going to try a charger for a Dell Streak 7.. see if it works.

Mine is also very picky. I used the stock Asus charger with a longer micro usb cable and it didn't charge while I was using the tablet over a period of around an hour. It maintained the % charge of the battery but didn't increase it. When I went back to the stock cable, it charged during use. Wouldn't be a real big deal if they hadn't scrimped on the cable to where it's only 3 feet long. What a pain.

A little OT, but my ASUS 1366 motherboard has an update you can install that allows the USB ports to charge an iPad at 1 amp instead of the normal .5 amp. I haven't tried it with the N7, but I suspect it won't work. Maybe another update will be released considering they make both devices, although my mb is kind of old...2009. I wonder if the USB2 specs allow for 2A charging and also if the newer USB3 spec allows more amps to be provided. If it doesn't, it should considering some of the latest power hungry devices.
Sent from my Nexus 7 using xda app-developers app

I looked at this too, and tried a few different configurations.
Measurements taken with my N7 at 95% charge. I expect higher power draw at lower charge.
.445mA - PC USB port
.440mA - APC USB battery pack directly connected
.443mA - iPhone 3G USB charger
.820mA - stock charger
.815mA - APC USB battery pack with D+/- disconnected at the host and shorted at the device end (actually 10 ohm resistor)
.818mA - APC USB battery pack with D+/- removed on host, shorted on device, and resistor divider for 1.2V on both pins (Samsung type)
I chose the APC battery pack as it provides a solid 5V at 1A. It also has D+/- wired iPhone-style.
Wondering what the charger driver thinks of this, I looked at dmesg just after every attempt. I see:
connected to PC USB:
Code:
smb347_charger: [cable_type_detect] Reg3F : 0xc0
smb347_charger: [cable_type_detect] Reg3E : 0x0c
Cable: SDP
========================================================
battery_callback usb_cable_state = 0
========================================================
connected to iPhone or APC charger:
Code:
smb347_charger: [cable_type_detect] Reg3F : 0xc0
smb347_charger: [cable_type_detect] Reg3E : 0x0b
Cable: OTHER
========================================================
battery_callback usb_cable_state = 0
========================================================
connected to stock, or APC with either of my adapters (cut & shorted or Samsung):
Code:
smb347_charger: [cable_type_detect] Reg3F : 0x83
smb347_charger: [cable_type_detect] Reg3E : 0x0a
Cable: DCP
========================================================
battery_callback usb_cable_state = 3
========================================================
So the charger limits to ~500mA when using an iPhone-pinned charger (OTHER) or a live USB host (SDP), and allows high current charging when D+/- is shorted regardless of being pulled to a given voltage. SDP is USB 2.0. charging spec terminology for Stanard Device Port, meaning a 500mA limited USB port, while DCP means Dedicated Charging Port which means that D+/- are shorted and can supply up to 1.5A.
This uses the SMB347 USB charge controller, same as the Kindle Fire, which works the exact same way.
TL;DR: Cut D+/- between the charger and device and short D+/- at the device for full current charging.

Charge tab 2 via usb!!!

As we know that we can not charge tab 2 via usb when connected to pc.
But there is a way:
do not insert whole usb to port at once.slowly insert the usb(connected to tab) to port(of pc) upto its approx 1/2-3/4 portion.you will see charging symbol on tab battery icon.it may take some time to figure it out.but it works.....
Note:it works on p3100 for sure and may work other models.
ENJOY!do not forget to hit thanx button...

a video demo how to do this should help :cyclops:
it works! thanks for the tips

i charged my tab via my computer. although it has an x above the battery it still charges.

mad5870 said:
i charged my tab via my computer. although it has an x above the battery it still charges.
Click to expand...
Click to collapse
no buddy if tab shows a x on battery that means it is not charging and tab is connected in kies/media device mode.but he you follow above method tab will show charging on battery.

I charge mine, with my galaxy note charger
Sent from my GT-P3100 using xda app-developers app

I jus got my tab 2 but it charges through usb... no tricks needed... it's slow though
cheers
B

berre said:
I jus got my tab 2 but it charges through usb... no tricks needed... it's slow though
cheers
B
Click to expand...
Click to collapse
which model you have?

I swear mine charges through the usb hooked up in the usb ports in the back of my desktop. I'll check in the am when we get a blown transformer fixed and the power back on. It's 99 degrees and will be a long night. :banghead:
Sent from my HTC One X using xda premium

Mine charges even when it has a x on the battery......
Sent from my GT-P3113 using XDA Premium App

Even mine charges....I have GT P3113

Droidlover123 said:
which model you have?
Click to expand...
Click to collapse
P5100
cheers
B

I wanted to add a clarification: when plugged into USB the notification popup indicates "discharging". But in fact it is charging, because the % charge goes up (slowly) with time.
The trick mentioned in this thread may make the tablet show 'charging', but I doubt that it makes any difference to whether it is really charging or not. The charge rate is determined by the max amps of the charger. The supplied Samsung charger is rated approx 2A; if you use the USB from the iPhone charger it is approx 1A (if you have USB 3.0 ports, that is also about 1A); but USB 2.0 gives you only 0.5A.

As said...charging over USB is painfully slow (2,5-5W). I prefer to charge it with the original adapter (10W )

Chuckles960 said:
The charge rate is determined by the max amps of the charger. The supplied Samsung charger is rated approx 2A; if you use the USB from the iPhone charger it is approx 1A (if you have USB 3.0 ports, that is also about 1A); but USB 2.0 gives you only 0.5A.
Click to expand...
Click to collapse
The tablet or phone will sense if the connection to the charger is AC mode or USB mode, if AC mode is detected then the tab will pull up to ~2.1 depending on the available rate from the charger, if USB mode is detected than the tablet will only draw ~0.5A.
The way the charger is configured will let the device know if it is an AC mode charger or if it is an USB mode charger.
By shorting pins 2 and 3 together on some chargers/cable the device will detect AC mode and it will pull more current.
I have a 1A 12V car charger that was wired for USB, an android device will see it as USB and pull only 0.5A, but an Apple device will pull the rated 1A. I shorted pins 2 and 3 and now android devices pull up to 1A, I am not sure but I think it is no longer compatible with apple devices (I don't own one).

It will say that it's not charging when plugged in via USB, but if you have it plugged in, it will charge, slowly. It takes forever if you're anywhere close to having a dead battery, and if you have wifi and other stuff turned on, it will take even longer but it should work, no tricks needed.

Thanks! Works on the 3113. It's shows charging and doesn't show as media device on the laptop. Nice find.

Hi.
I have a couple of these usb adaptors, see link below, I bought them years ago for the original 7" galaxy tab but i never used them.
If i plug my tab2 into an usb2 port i get the red cross on the battery icon, so i tried one of these adaptor and my tab2 is charging from an usb2.0 port on my notebook and according to battery monitor widget pro at 14% an hour, and i have a lightning bolt sign in the green battery icon.
I did a search for the adaptor i bought and i think i have found it for £6.50 each, see link below.
http://www.mytrendyphone.co.uk/shop/samsung-p1000-galaxy-63928p.html
John.

the tablet charges anyway so the icon says no
In 4.0.4 rom the charge icon its fixed, anyway charge by USB is too, too slow, only use for emergency

Droidlover123 said:
no buddy if tab shows a x on battery that means it is not charging and tab is connected in kies/media device mode.but he you follow above method tab will show charging on battery.
Click to expand...
Click to collapse
not trying to be a smartass but i know when my tab goes from 5% to a 100% while plugged in to my computer its charging. and yes still had the x.
Sent from my SPH-D710 using xda app-developers app

Mine P 3100 international version even x on battery while usb connected but still its slowly charging this occurred aso to tab 1 and tab 10.1 SII and note