Database Users

Speed of charge

I've tried searching, but came up with nothing (not even on Google).
It seems to me that my HD2 charges up much quicker when connected to the mains than it does when charging via USB - is this correct ? I'd prefer to only charge via USB as, that way, the phone is still syncing, but it sometimes takes forever to get to full charge that way.
Just wanted to get others' opinions on this.

wilsojer said:
I've tried searching, but came up with nothing (not even on Google).
It seems to me that my HD2 charges up much quicker when connected to the mains than it does when charging via USB - is this correct ? I'd prefer to only charge via USB as, that way, the phone is still syncing, but it sometimes takes forever to get to full charge that way.
Just wanted to get others' opinions on this.
Click to expand...
Click to collapse
The wall charger charges at 1 amp.
USB, with a powered USB socket, will max out at half that due to the 500mA standard that USB uses.
So, in theory, it should take twice as long to charge on USB alone.

Plus the 500mA limit on USB is spread across several physical ports, so if you have anything else plugged in then you'll be charging at an even lower rate.

Good to know - thanks, guys - I learnt something new today
Guess I'll charge via mains going forward.
Thanks again !

plus when connected to active sync the phone is on, when its I wall charger it will be on standby.

Despite HTC shipping a 1A charger (which is the most I've ever seen for a USB charger) Lion battery prefer not to get cooked while charging and would last longer if charged at 500ma.

rp-x1 said:
The wall charger charges at 1 amp.
USB, with a powered USB socket, will max out at half that due to the 500mA standard that USB uses.
So, in theory, it should take twice as long to charge on USB alone.
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Click to collapse
samsamuel said:
plus when connected to active sync the phone is on, when its I wall charger it will be on standby.
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Click to collapse
Exact, the phone actually limits what it draws from an USB port to about 450mA (some safety margin). Then, is stays powered on and active (due to ActiveSync running), drawing approx 100mA. So it actually charges at about 450-100= 350mA, taking ridiculously long (4-5h) to charge. With the supplied charger it charges at 850mA.
Aterlatus said:
Plus the 500mA limit on USB is spread across several physical ports, so if you have anything else plugged in then you'll be charging at an even lower rate.
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Click to collapse
Wrong, each port gets 500mA.
airwater9 said:
Despite HTC shipping a 1A charger (which is the most I've ever seen for a USB charger) Lion battery prefer not to get cooked while charging and would last longer if charged at 500ma.
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Click to collapse
Li batteries support 1C charge without drawback (would be 1.32A for the HD2's battery).

Wrong, each port gets 500mA.
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Click to collapse
Incorrect. The USB standard requires 500mAh nominal at any port when used alone. Manufacturers then decide whether they will "over specify" or not. You will not get 2mAh from a 4 port USB bus unless the internal power supply its built for it and many are not. Current is drawn by the device and if the draw exceeds the supply rating then there is a shortfall to all devices. It all depends on how well the equipment is specified and there its wide variation.

More details about charging here

pa49 said:
Incorrect. The USB standard requires 500mAh nominal at any port when used alone.
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Read page 171 of the USB 2.0 specification:
Root port hubs: Are directly attached to the USB Host Controller. Hub power is derived from the same
source as the Host Controller. Systems that obtain operating power externally, either AC or DC, must
supply at least five unit loads to each port. Such ports are called high-power ports. Battery-powered
systems may supply either one or five unit loads. Ports that can supply only one unit load are termed lowpower
ports.
Click to expand...
Click to collapse
A port is either low power, in which case it can supply 1 unit load (100mA), or high power, which can supply 500mA. There's no spreading between ports, for each port if it's a high power one it must be able to supply 500mA at any time, if it's a low power one it will never provide more than 100mA. So there's no such thing as one that provides 500mA if used alone and less if others are connected... or the manufacturer is violating the spec.
Note that low power ports pretty much don't exist on PCs. They can be found on multimedia players with host function for example, which are just good to power a USB key or card reader.
Further on the page you can see that with hubs that don't have external power, the output ports are required to be low power ones, so that a 4-port hub can give one of the 5 unit loads it receives to each port, plus one for its own power, so you can't draw 500mA on any port of a bus-powered hub and be within spec.
Now if you could refrain from misleading users... can't count anymore how many times I've corrected you on your firm affirmations...

[Q] Charging Craziness

I can't figure this phone out with regard to charging.
1) Won't charge via computer USB (I've heard the reasoning for this - still seems stupid)
2) Charging w/ 1amp 5V wall charger - phone screen is non responsive to touch, but phone charges (unplugging it unfreezes the screen)
3) 1amp accessory USB charger, won't charge the phone at all.
Are the charging limitations software or hardware based. I can't come to terms with the fact that this phone can't at least charge by USB. It doesn't need to be lightening fast, but it should at least charge.
Is there anything that can be done?

are u using OEM charger and USB cable ?

charging by USB
My phone charges with just the USB cord and a PC, It is a bit slow to charge that way, but it charges. Are you sure you are using a powered USB port?

it will charge via USB, you just need to install the motorola drivers. it needs more current than the original USB standards allowed for. USB can provide that current now, but you need the drivers.

Not OEM
None of the above are OEM chargers and the cables are no OEM either (Wouldn't think the cable has anything to do with it).
Since i am out and about a bit, i have to have a portable battery powered backup charger, i also carry a wall/car charger that is capable of doing both at the same time.

cable has nothing to do with it. The power requirements are strict for this phone, and it's all down to the proper way to charge the battery.
I know for a fact that the generic energizer car charger i picked up with interchangeable ends for different USB types works perfectly for this phone. It might be worth it to just jump on ebay and grab another OEM battery instead of trying to run around with chargers.

have you measured the output of those 1a chargers? i have an adapter from china that says 1a but only puts out 0.3a and doesnt charge my atrix either.

I am still using the chargers I had from my blackberry 8900. The bb wall charger works great. The car charger (att) with the flip cover over a usb makes my phone hot as hell but it still charges.

Think i've also found that, once you have the motorola drivers installed on your computer, disabling the data connection to the phone (as in selecting "None" for the USB connection option in the notification pane after you connect the phone) seems to allow the phone to charge a fair bit faster over USB. Kinda makes sense too when you're thinking about it... since it wouldn't be constantly accessing the phone as a storage device.

Yes some wall chargers dont work i.e. the two I had from my Nexus One, BB chargers seem to work well as I believe they needed more juice to charge in the first place, for the usb cable, the best solution to try is getting the updated usb drivers as mentioned.

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?
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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

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.
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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.
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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.
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Click to collapse
Great find.

Pretty sure it just bridges the data pins.

Charge from USB

I figured I would share this since I have not found another thread with this info.
The Galaxy Note 10.1 will charge from usb.
I find this interesting because no tablet, at least none I have known, will do this. They all need to be actually plugged into a wall outlet to charge. However, my note 10.1 has charged from around 13% to 32% plugged into USB. Now, mind you , it doesnt charge very fast, but it does charge.
For some this won't matter. In my case, that 3 ft cord doesnt go from the floor outlet to my desk at work too easily, but the usb will plug in very easily and reach where I need it too. At the very least, it will add a little more time to the length of the batter. I work a 10 hour shift, not adding in the hour for lunch, and I can usually made it about 8 hours. So this may get me the extra two hours I need...hopefully.

phoenixbennu said:
I figured I would share this since I have not found another thread with this info.
The Galaxy Note 10.1 will charge from usb.
I find this interesting because no tablet, at least none I have known, will do this. They all need to be actually plugged into a wall outlet to charge. However, my note 10.1 has charged from around 13% to 32% plugged into USB. Now, mind you , it doesnt charge very fast, but it does charge.
For some this won't matter. In my case, that 3 ft cord doesnt go from the floor outlet to my desk at work too easily, but the usb will plug in very easily and reach where I need it too. At the very least, it will add a little more time to the length of the batter. I work a 10 hour shift, not adding in the hour for lunch, and I can usually made it about 8 hours. So this may get me the extra two hours I need...hopefully.
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Click to collapse
Hmm, I think mine claims not to (it puts an X on the battery icon), but I didn't leave it plugged into my computer long enough to see whether it charged or not. I think all tablets can potentially charge via USB port on a PC, it's just that most disable it out of the box but eg. for the Galaxy Tab 10.1 custom kernels could enable charging over USB.

iofthestorm said:
Hmm, I think mine claims not to (it puts an X on the battery icon), but I didn't leave it plugged into my computer long enough to see whether it charged or not. I think all tablets can potentially charge via USB port on a PC, it's just that most disable it out of the box but eg. for the Galaxy Tab 10.1 custom kernels could enable charging over USB.
Click to expand...
Click to collapse
Mine also puts the RED X over the battery icon whether I try to charge it through a PC USB port or other USB charging port other than the Samsung adapter (Goal Zero 150 usb port and Panatech 10000mah external USB battery pack). The tablet shows that it is charging when i view it using GO POWER MASTER app. Watched it for 5 minutes but with WIFI off, it still dropped from 88% to 87%. I am however using the stock kernel.

It charges faster if you have the screen off. The usb gives more or less what you need to keep it running with the screen on.
Skickat från min GT-I9300 via Tapatalk 2

Mine put the red X on the battery icon as well, but still charged. I had to have the screen off.
I had mind plugged into my USB 3.0 port (which should really make a difference) to transfer some files, and then just left it plugged in and it charges. Its definitely a trickle charge, but I am glad to see it does this, as my a500 did not.

When I transferred 40Gb of data to the mSD via MTP (screen off) and called up the batt-graph after disconnection it showed me a fair charging rate. Not stunning but at least a noticeable charge ( from 63% to 82% in three hours).

So it does charge the battery, in spite of the red X?

Yes it does, albeit very slowly.

You guys are misinterpreting the red x. Just got off the phone with Samsung. The x stands for "extra awesome charging". I swear.
Sent from my GT-N8013 using Tapatalk 2

phoenixbennu said:
I figured I would share this since I have not found another thread with this info.
The Galaxy Note 10.1 will charge from usb.
I find this interesting because no tablet, at least none I have known, will do this. They all need to be actually plugged into a wall outlet to charge. However, my note 10.1 has charged from around 13% to 32% plugged into USB. Now, mind you , it doesnt charge very fast, but it does charge.
For some this won't matter. In my case, that 3 ft cord doesnt go from the floor outlet to my desk at work too easily, but the usb will plug in very easily and reach where I need it too. At the very least, it will add a little more time to the length of the batter. I work a 10 hour shift, not adding in the hour for lunch, and I can usually made it about 8 hours. So this may get me the extra two hours I need...hopefully.
Click to expand...
Click to collapse
Interesting, because every tablet I've owned (Tab 10.1 and Nexus 7) behaved like this.
They will charge VERY slowly on USB - and will likely not charge at all if the screen is on due to the total unit power consumption being >500 mA.

Entropy512 said:
Interesting, because every tablet I've owned (Tab 10.1 and Nexus 7) behaved like this.
They will charge VERY slowly on USB - and will likely not charge at all if the screen is on due to the total unit power consumption being >500 mA.
Click to expand...
Click to collapse
Same here. iPads, nook color, Samsung tablets, all say not charging but do trickle charge if you are doing anything to drain it faster than thenusb can supply. It takes around 8 to 10 hours to charge my gt101 through regular USB 2.0.

mitchellvii said:
You guys are misinterpreting the red x. Just got off the phone with Samsung. The x stands for "extra awesome charging". I swear.
Sent from my GT-N8013 using Tapatalk 2
Click to expand...
Click to collapse
Bwahahaha... A friend of mine posted on twitter that Apple should make something that lets iDevices charge each other... Ours actually can because of USB host! I actually lost the usb host adapter for my old galaxy tab so I need to get a new one but I had one for my gs3, and it does charge my tablet. But the reverse is clearly more useful.
Sent from my SCH-I535 using Tapatalk 2

Tested again when attached to Notebook by USB:
Screen on at max. Brightness and working: batt charge stays level
Screen off: batt charges approx. 5% per hour
Tested on GNote charger (1A output)
Screen on : charging very slowly (approx. 3% per hour)
Screen off: charging approx. 8% per hour
Tested on iPad charger:
Slower than original charger although max. Output:

The more items you have attacht to your computers USB the less power it has to allow your tablet to draw for charging.

donec said:
The more items you have attacht to your computers USB the less power it has to allow your tablet to draw for charging.
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Click to collapse
I don't think this is the case. The USB ports provide a set power output, and not variable by available power supply type of output.

phoenixbennu said:
I don't think this is the case. The USB ports provide a set power output, and not variable by available power supply type of output.
Click to expand...
Click to collapse
You are correct they are not variable but they only have a given amount ofpwer available and if you are drawing the max and add another device that needs more power to charge the power will not be available.

donec said:
You are correct they are not variable but they only have a given amount ofpwer available and if you are drawing the max and add another device that needs more power to charge the power will not be available.
Click to expand...
Click to collapse
Of course, everything has a limited power availability, USB ports being no exception, whether having their own psu or bus powered or whatever your setup may be, but unless you are doing something beyond practical use or have a poorly designed setup, than this should not be a problem. I know some systems out there, the mac book pro for example, specific limits USB power output between ports by design (you may even call it variable haha...but by design). However, in a general sense, you should not have a power output issue with simply plugging in for usb charging., even if all other ports are used up as well. So don't daisy chain, or do anything like that. Practical use should be fine. I personally hook my usb charged devices, like my phone, to my monitor at work. It was a few usb ports on the side, and it works great. Also, it keeps me from having to deal with all the annoying security popups that go with plugging it into the actual computer.
In a probably unfunny but still remotely amusing anecdote, I remember the massive work I put my a500 through. I used to have a usb hub attached with 2 1tb portable hard drives, a keyboard, a mouse, my phones, and more all charging directly from USB. Never had trouble with power issues, aside from quicker draining of the battery. lol.

does anyone know if charging is possible when you use an Y adapter on USB-OTG to hook up an external harddrive and a charger at the same time?

cproaudio said:
does anyone know if charging is possible when you use an Y adapter on USB-OTG to hook up an external harddrive and a charger at the same time?
Click to expand...
Click to collapse
Barring any specific device hardware limitations, it is possible to do data transfer and power transfer at the same time using a y cable. Its essentially the same thing as using a usb hub, except you only have two ports instead of 4 or more.
As for actual practical use on the note, I have not tried it out, and I am not aware of any limitations built into software or hardware to prevent it. So, I do not see you having a problem with it.

Almost all tablets can charge through regular USB2 if they're sleeping (or better - powered off).
USB has power limits (USB1.1 is 100mA, USB2.0 is 500mA and USB3 is 2A) BUT these are the 'minimum maximums', if you will. That is, these are the current source *required* for certification. It's entirely permissable for a USB port to provide as much current as it wants - it just can't be limited to *less* than these amounts.
USB 2.0 and later ports are also supposed to implement 'overcurrent' warnings if the device is taking more current than the port can provide..
That's why, for example, some ports can drive a CDROM or external HD drive without a problem - while other ones can't.
The Note 10.1 needs a little over 2A @ 5V to charge at a reasonable rate.
One other note, if you let your battery drain very low, then the lower current of most USB 2 ports won't be enough to charge it even if it's off. The charge current curve isn't linear.