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Fast charging N1

It seems the only way to fast charge a N1 is with the supplied wall charger. Standard Micro USB chargers whould only allow at much as 450mA of charge current regardless of the adapter current capacity.
The bundled charger however, manages to push 900mA into the N1. I made a cut in the charger wires and measured the current draw to make sure.
Now.. I'd like my car charger to be able to do the same. There must be some hack in the plug of the N1 charger since there are only 2 conductors from the case to the plug. You can see that the plug is somewhat longer than similar Micro USB plugs..
So I tried to see if one of the 3 unused pins can tell me anything but.. they seem unconnected as far as I could tell. Diode measurement (to test for any digital part inside) also did not produce any results. The next obvious step is to take the molded plug apart but I'd rather not...
Does anyone have any clue as to what makes that plug so special?
And please - I did my tests with a bench power supply - not the car chargers - so don't go around telling me it has to do with charger current capacity.
Thanks,
Nir

are you sure the micro usb cords you are using are able to handle the amps? most chargers made prior to now, only push about 450mA, the G1, and N1 chargers i have push a full amp though. I just ordered a car charger that pushes an amp too. There is nothing "special" about the plug.

followinginsanity said:
are you sure the micro usb cords you are using are able to handle the amps? most chargers made prior to now, only push about 450mA, the G1, and N1 chargers i have push a full amp though. I just ordered a car charger that pushes an amp too. There is nothing "special" about the plug.
Click to expand...
Click to collapse
I beg to differ. All the cords can easily supply 1 AMP. It is the phone itself that decides how much to draw from the charger based on something IN THE PLUG.
I am an electronics engineer so do understand I know perfectly what I am talking about
And your 1A car charger does not supply anything over 0.45A to the phone.. you will see that if you are using the phone while it charges (say nav or phone call) the phone actually looses some charge albeit it being charged... This will not happen with the stock wall charger.

I have a 900mAh car charger that I use and it does in fact give 900mAh to the phone while charging. I can tell because I used a 450mAh charger at home before and it was slooow and I could drain my phone while charging it. With the car charger I can stream music with spotify, use the GPS, have the screen on full brightness and the battery % will still go up.
I also bought a new wall charger recently, which is 850mAh on the USB port and has a 350mAh charger for a loose battery as well, works quite nice.

Has anyone measured the voltage or put a scope on the output of the stock charger?
maybe stock charger has a slight variance in voltage over USB chargers or some signalling going on and this tells the N1 to take more current from it?
I would like a solution to this too I've seen my phone discharge while on a supposedly 1A car charger using co-pilot.

SBS_ said:
I have a 900mAh car charger that I use and it does in fact give 900mAh to the phone while charging. I can tell because I used a 450mAh charger at home before and it was slooow and I could drain my phone while charging it. With the car charger I can stream music with spotify, use the GPS, have the screen on full brightness and the battery % will still go up.
I also bought a new wall charger recently, which is 850mAh on the USB port and has a 350mAh charger for a loose battery as well, works quite nice.
Click to expand...
Click to collapse
Forget the numbers on the chargers - what counts is what really goes into the phone and that needs to be measured with a current meter (test equipment). What you may think to be fast might not be that.
Original HTC chargers obviously do the trick of fast charging but this comes at a price compared to the $3-$4 garden variety on Ebay and the likes.

now I cannot help you with the electronics at all, but, my old HTC Touch Pro charger seems to charge the same as the one which came with the phone, is this correct?
(suits me if it is, as then I have a charger for home and work)
my blackberry bold 2 charger only says it outputs 700MAh, but both the google and htc chargers both say 1.0A

dnts said:
Forget the numbers on the chargers - what counts is what really goes into the phone and that needs to be measured with a current meter (test equipment). What you may think to be fast might not be that.
Original HTC chargers obviously do the trick of fast charging but this comes at a price compared to the $3-$4 garden variety on Ebay and the likes.
Click to expand...
Click to collapse
Yes, it is just anecdotal evidence as I don't have any equipment to measure it. But my phone no longer discharges when I use it while charging, which it used to do with the old charger I used. So while I can say for a fact that the charger I use now is faster, I can't say by how much (this goes for both the car charger and the one I put in the wall socket).

I ordered this charger a few weeks ago and it charges my phone as fast as the original charger. The label says 5v / 1200mA.
Genuine Nokia Mini AC-10U US Type AC Charger (100~240V)
$7,25 and free shipping. (Takes a while before you get it tho.)
GazzaK said:
now I cannot help you with the electronics at all, but, my old HTC Touch Pro charger seems to charge the same as the one which came with the phone, is this correct?
Click to expand...
Click to collapse
HTC Touch Pro = mini USB
Nexus One = micro USB

Not an engineering here, but I am guessing the phone not always drawing more than 500ma may be is to do with the charger itself.
There is this "fast charge" USB standard where a wall plug has the USB data pins shorted to indicate that it is a wall plug and hence the phone knows when to draw more power. So even if the charger is rated 1A, the phone might not know if it could utilize that if those pins aren't shorted. Try doing a quick Google on this ....
If someone can test if the stock charger that came with the phone in fact does have those pins shorted that would confirm part of this theory.

For all practical purpose - I used two cables/plugs with a bench adjustable power supply. Simple micro USB plug would only let me draw 450mA regardless of power supply voltage in the range 4.5-5.5V. Tried shorting data pins - nothing. Tried shorting spare pin to VCC or GND or any of the other pins - nothing.
Used original cable and plug - draws 900mA at voltages from 4.9-5.5.
So it's in the plug somehow.
Tried (very difficult) to see if the pins on the plug are shorted and all 3 spares (except for 5V and GND) seems unconnected.
Next step is the irreversible hot knife...

I'm bugged by this, too. I tested with my desktop dock connected to my car charger (which states 1000 mA): it loads slowly and my battery widget reports USB- instead of AC-charger.
Might it be that the phone tries to load more than 1000 mA at the beginning to be sure that it doesn't overload the charger? And if that fails, it falls back to 500 mA?

Could N1 use a simple logic of:
- always watch the voltage
- start drawing 500ma (or whichever is the lowest current as per USB spec)
- increment in say 50ma steps
- if voltage drops below 4.x V, back off and stay at that level

I just did a little test of my own. I have a Palm Pre car charger (actual Palm brand one labeled as 1000ma output) and I plunged my N1 into it on my way home from work. In twenty eight minutes, my battery went from 47% to 70%. Much faster than plugging into my computer, which is 500ma max. I don't have any fancy test equipment, and don't claim to know a whole lot about electronics, but seems pretty fast to me.

I have a 4-port 2A 5v USB charger, and connecting it to my Nexus OR Milestone with a MicroUSB cable (the one that shipped with either phone, or the one from my Kindle) yields painfully slow charging - it basically won't charge if you are using the phone.
Connecting the Nexus One charger yields fast charging on either phone - so it is not HTC (or Motorola) proprietary.
The Milestone comes with a 900mA USB plug, and connecting THAT to either phone with either of the MicroUSB cables yields fast charging.
I have another aftermarket 2 port 2A 5V USB wall charger (brand: T'nB) AND I have an iPhone USB plug, and both give fast charging on the Milestone, and I have not yet tried them on the Nexus One.
Breakdown (on things I've tried):
FAST CHARGING on Nexus One AND Milestone:
Nexus charger (either in the US (110v/60hz) or in France (220v/50hz) through an adaptor)
Milestone wall French USB plug (which I think is something odd like 850mA at 5.9v) with ANY microUSB cable (in fact, it seems to charge both of the phones faster than the stock Nexus One plug)
SLOW CHARGING on Nexus One AND Milestone:
USB plug on computer
One aftermarket 4 port 2A 5V USB charger (NOT a hub, only a charger)
FAST CHARGING on Milestone, untested with Nexus One
T'nB 2 port 5v 2A USB wall charger
Apple iPhone 1 port 1A 5v USB wall adaptor

Seems found the answer for Fast Charging N1
I had just do some test for Charging N1 With Original AC Charger , Other band USB Charger and PC USB charger.
1. Orginal Charger give N1 from 0% to 100% at about 2 hour and something.
2. The other band AC charger and PC USB Charger can only finish the same job over 5 to 6 hours.
The Fast Charging is Due to 5.1V (Measured at N1) and 5.2V(Measured inside AC charger). 0.1V Drop is due to resistance of USB cable.
The Slow charged is due to 4.8V (measured at N1) and 5.0V (measured on PC USB and Other AC Charger)
i.e. Original Charger mod from 5.0 V to 5.2V (about 10% increase in Voltage)

Looks my theory is correct then ? N1 watches the voltage and if it droops too much, it backs off the current.
So the key would be: get a charger than can maintain at least 1A @ 5.2V, use
a decent gauge, short wire from the brick to N1.

Has anyone tried a Blackberry charger on the N1? Will they work to full capacity as well? (They're on Amazon for a fiver)

Because the nokia charger is working
http://pinoutsguide.com/CellularPhones-Nokia/micro_usb_connector_pinout.shtml
see info under table.
I tested also HP charger + standard USB cable delivered with Nexus, and it is charching cca 1A.
Then I tested one noname Carcharger + standard USB cable delivered with Nexus, and also charging cca 1A.
I dismantle the noname carcharger and here is a result:
data line (pin2+3) is shorted and connected do + (pin1 ,Vcc) thrue resistor cca 630kOhm.
1 - 4 = 5.1V
2,3 - 4 = 3.2V
rashid11 said:
Looks my theory is correct then ? N1 watches the voltage and if it droops too much, it backs off the current.
So the key would be: get a charger than can maintain at least 1A @ 5.2V, use
a decent gauge, short wire from the brick to N1.
Click to expand...
Click to collapse
I try to use power supply 5.2V 2A with cable without dataline (pin 2and3 not connected) and it is charging 480mA only.

I have now tested with an HTC car charger for the HD2. It's fast charging (tested with Waze running, two bluetooth connections and playing mp3 - and it's still loading the battery, whereas before it would be stuck at the current percentage) and even shows AC power instead of USB.

[Q] Are all USB Charges the Same?

I have about 5 Micro USB wall charger laying around, so when I got my Captivate I was happy to see that it used a Micro USB.
My question is.... Is all of the Micro USB power supplies the same? the ones i have are from different Motorola phones.
Thanks,

Coldheat1906 said:
I have about 5 Micro USB wall charger laying around, so when I got my Captivate I was happy to see that it used a Micro USB.
My question is.... Is all of the Micro USB power supplies the same? the ones i have are from different Motorola phones.
Thanks,
Click to expand...
Click to collapse
I assume you mean the wall charger. The charger and the cable are actually separate. You can plug any USB cable into this that has a female USB end. The other end could be mini, micro, ipod, or something else.
They are not all the same - the Moto charger delivers more Amps then the Captivate. Some charger deliver less. The phone will only draw what it is set to, so you can use just about all of them.

cool thanks

The short answer: It's probably fine
The long answer:
USB is a specification, so anything using usb should be designed to run at (for USB 2.0) 4.4-5.25 V. It *should* be fine for charging any microUSB device (the "U" is for "Universal") but I guess it's possible (though unlikely) that the company that made the charger did something funky/proprietary with the voltage/amperage, which would make it not USB even though it uses a USB port. See if the charger says the operating voltage/current on it. It should say around 5V and somewhere in the range of 150-900 mA. If it does, you're golden, if it doesn't say you're still probably fine.

The phone is actually quite picky about chargers. It can recognize a USB charger in either (1) AC wall charger or (2) USB charger. If your paritular charger can be recognized as AC charger, it can be charged in a faster rate if your wall charger can deliver. The Captivate comes with a 700ma wall charger. Some can deliver 1000ma or even higher but Captivate internally limits to 1000ma max from what I read. The higher the amprage, the faster it can charge the battery.
On the other hand, if your charger is recognized as USB charger, not only you will be prompted to select USB mode (if you configured to do so) as if you connect it to a PC, you will also be limited to maximum of 500ma of charging current per USB standard. It will be slower than the stock charger (which is slow already).

foxbat121 said:
The phone is actually quite picky about chargers. It can recognize a USB charger in either (1) AC wall charger or (2) USB charger. If your paritular charger can be recognized as AC charger, it can be charged in a faster rate if your wall charger can deliver. The Captivate comes with a 700ma wall charger. Some can deliver 1000ma or even higher but Captivate internally limits to 1000ma max from what I read. The higher the amprage, the faster it can charge the battery.
On the other hand, if your charger is recognized as USB charger, not only you will be prompted to select USB mode (if you configured to do so) as if you connect it to a PC, you will also be limited to maximum of 500ma of charging current per USB standard. It will be slower than the stock charger (which is slow already).
Click to expand...
Click to collapse
It is not "picky" it follows the USB specifications. For instance I have a 4 port USB wall charger that is capable of supplying 5 volts at 2000 mA to one port or 5v @ 500 mA to 4 ports. Unfortunately the charger is not complex enough to know how many devices are plugged in at once and therefore always signals to all devices to only use a maximum of 500 mA. So if those devices follow the specs they will only draw 500 mA max since it is seen as a high current device (low current devices only should draw 100 mA max).
I DO NOT RECOMMEND ANYONE OPEN UP ANY ELECTRICS EVER ESPECIALLY ONES WHEN CONNECTED TO THE AC LINES IN YOUR HOMES. IT IS A FIRE AND ELECTROCUTION RISK AND I NOR ANYONE ELSE TAKE RESPONSIBILITY FOR YOUR OWN STUPIDITY.
However I hacked it by adding a resistor of proper value between the data pins so that the phone if it wanted to could use the full 2000 mA. Know whenever plugged into that USB port the phone goes into AC mode and from some rough testing during the bulk charging phase the phone charges at a rate of 40% per hour instead of the USB modes 20% per hour. With this hack it takes roughly 3 hours to fully charge since the final charging stage of lithium batteries requires the current to slowly be dialed back. Thats a lot better than the USB modes 5 hours.

icedfire101 said:
It is not "picky" it follows the USB specifications.
Click to expand...
Click to collapse
I say it is picky because without hacking it will only use USB mode for most wall chargers and car chargers out there. It probably won't be any problem for a slow wall charger. But for car charger, 500ma is simply not enough if you also run GPS navigation. The phone uses more than 500ma of juice in that mode. I've to hack my car charger (a 700ma USB charger designed for iPod etc) couple times to let it reliably recognize as AC charger.

foxbat121 said:
I say it is picky because without hacking it will only use USB mode for most wall chargers and car chargers out there. It probably won't be any problem for a slow wall charger. But for car charger, 500ma is simply not enough if you also run GPS navigation. The phone uses more than 500ma of juice in that mode. I've to hack my car charger (a 700ma USB charger designed for iPod etc) couple times to let it reliably recognize as AC charger.
Click to expand...
Click to collapse
Again that is not "picky" it is doing what it is suppose to. What we really need are companies that will follow the USB standards and make Dedicated Charging Ports on there chargers. Most companies cheap out and only make 500 mA and 700 mA products (which that is why charging is so slow). Then they sell it to consumers that don't know any better. Especially with the 700 mA chargers since consumers will think that it is better because of the bigger number but devices that properly follow the USB spec will still only draw 500 mA. (I don't know what specifications Apple follows with their device but since a lot of those that I see with 700 mA are geared toward apples device they may be able to make use of them.) I know of no open specification for a USB device to pull 700 mA.
As to why the Samsung stock charger that came with the phone is 700 mA, I m guessing it is because of cost again. I can tell you though that it doesn't short the data lines with the proper X ohm resister for a Dedicated Charging Port. So I m thinking they made their own proprietary standard there just so they could save a few bucks on each charger but still give the consumer something to feel good about for buying there overpriced stuff.
I DO NOT RECOMMEND ANYONE OPENING UP ANY ELECTRONICS, EVER. ESPECIALLY ONES CONNECTED TO THE AC LINES IN YOUR HOMES. IT IS A FIRE AND ELECTROCUTION RISK AND I NOR ANYONE ELSE TAKE RESPONSIBILITY FOR YOUR OWN STUPIDITY.
Dedicated Charging Ports are required to supply 1800 mA. That means if you try and hack a device that is only rated at 700 mA to be a Dedicated Charging Port the device will possibly overheat and die or cause a fire if any device actually tries to pull the 1800 mA.
As far as car chargers: It is very simple to make a Dedicated Charging Port for a car charger provided you have an old USB one you can mod. Just get a DC-to-DC converter that will convert 11-14 volts (your car battery's voltage range) to 5 volts and throw a X ohm resistor on the USB data pins. Put it all in the empty shell of the donor and your done.

Not all charging methods created equal?

I am really frustrated with charging my phone.
From the wall, using the stock 700mA Samsung charger, I get 5% every 10 min.
From a USB cigarette lighter charger modified to source 750mA, I get 3% every 10 min.
From a USB cigarette lighter charger that can source 3A, I get hardly anything.
I assume from these findings that one or more of the following is true:
1. The phone knows when it is plugged into a stock charger.
2. The phone has a current limiter that prevents overcharging.
Does anyone have a charger, other than stock, that they recommend?
I'm half tempted to hook my stock charger up to a cigarette lighter inverter and power it that way.
(I'm also half-tempted to grab a current probe tomorrow and measure what the device is pulling.)

i havent really used my oem samsung wall charger much, but i know when i try to charge from my computers usb it takes 4EVER, thats why i jumped on this ebay deal

IBNobody said:
(I'm also half-tempted to grab a current probe tomorrow and measure what the device is pulling.)
Click to expand...
Click to collapse
I'd probe the chargers and see how accurate their ratings are as well....

does anyone know if using a 1mA charger would be okay? i have one left over from my evo.

The phone won't draw more than 500mA from a charger unless the USB data pins are connected.
Be careful, though... 99.9% of the chargers from China that claim to be 700mA (the nominal value of Samsung's) or 1A will overheat and die (or worse) if you try to actually draw that much current for any sustained length of time. I'd almost go so far as to say that it's SO EASY for a manufacturer to support high-power mode, I'd be automatically suspicious of any allegedly high power charger that doesn't ship with the pins shorted together.
Manufacturers know that most consumers don't know the difference (hell, most users HERE don't know the difference, and XDA is the upper crust elite of the Android phone universe), so they omit the shorting bridge and ship a charger with quoted power capacity that it MIGHT be able to sustain for a couple of minutes if you operated it in a walk-in freezer, knowing that most phones will never draw more than 500mA and it'll work fine for them. It lets them sell the charger for 99 cents AND pretend to be better than the others on the rack because it has a bigger "max power" value.
It's "RMS-vs-Peak" all over again.

Yeah I'm one of those that don't know much about the charging. I did figure there was a different charge rate when plugged into the wall and when plugged into usb or a usb converter like powerjolt.
I also found that one of the usb to micro's that I bought for using with my car powerjolt coverter won't let me connect via debugging/adb shell. was a little surprised at this... is it just a bad cord?

bitbang3r said:
The phone won't draw more than 500mA from a charger unless the USB data pins are connected.
Be careful, though... 99.9% of the chargers from China that claim to be 700mA (the nominal value of Samsung's) or 1A will overheat and die (or worse) if you try to actually draw that much current for any sustained length of time. I'd almost go so far as to say that it's SO EASY for a manufacturer to support high-power mode, I'd be automatically suspicious of any allegedly high power charger that doesn't ship with the pins shorted together.
Manufacturers know that most consumers don't know the difference (hell, most users HERE don't know the difference, and XDA is the upper crust elite of the Android phone universe), so they omit the shorting bridge and ship a charger with quoted power capacity that it MIGHT be able to sustain for a couple of minutes if you operated it in a walk-in freezer, knowing that most phones will never draw more than 500mA and it'll work fine for them. It lets them sell the charger for 99 cents AND pretend to be better than the others on the rack because it has a bigger "max power" value.
It's "RMS-vs-Peak" all over again.
Click to expand...
Click to collapse
D+ to D- must be shorted to get the high power mode? Maybe that was why my 3A supply was not handling it.

The Epic pulls 380mA when charging from a USB port from a Dell T3400 workstation. The result was steady at 40% and 80%.
I'll try out my other charging methods later and find out everything.
Stay tuned!
EDIT 1:
380mA is the magic number. It draws 380mA from all USB sources, including my two car chargers.
It draws 600mA from the wall adapter.
The wall adapter does indeed have D+ and D- shorted. My other chargers did not.
Here is the pinout for a USB port: http://pinouts.ru/Slots/USB_pinout.shtml
Here is the "beefy" USB charger I've been using:
http://www.wagan.com/index.php?page...ategory_id=22&option=com_virtuemart&Itemid=98
This charger is rather nice because the step-down supply (AX3002) has a large heatsink soldered to the ground tab.
It currently pulls up/down the D+/- lines via resistors. Each port is pulled down separately.
What I plan on doing next is to remove the pull resistors from one of the ports and short D+/- together.

Well, this explains a lot. This was really getting frustrating. I bought a "high-curent" charger for my car and the phone blows through the battery when I'm driving around with Maps running.

Im always on the road and for me an inverter in cigarette lighter with stock wall charger works best.the slowest charge is using stock usb cable since theres a slot for it on the inverter.2nd was radio shack car lighter in inverter.the inverter was from radio shack as well
Sent from my SPH-D700 using XDA App

IBNobody said:
Here is the pinout for a USB port: http://pinouts.ru/Slots/USB_pinout.shtml.
Click to expand...
Click to collapse
that is the official spec but there are actually not just four but six connectors on usb micro, which is how samsung can create a whole mess of pinut jumps for various amperage draws as well as data, entrainment dock and car dock.

[FAQ][10/11/10] Samsung Epic USB/Wall/Charger FAQ

This message is a summary of my previous messages. I hope that it will be useful. I wrote this to document what I found out about the Epic. I'm cheap, and I didn't want to buy ANOTHER charger for my car. I had a 3A, 2-port USB charger, and I was mad that my Epic was charging slowly. I managed to modify my charger to get it to perform just like the wall charger that came with my phone.
---
Q: How much current does the Epic draw from a normal (bus-powered) USB port when charging?
A: 380mA.
Q: How much current does the Epic draw from the OEM 700mA wall charger when charging?
A: 600mA
Q: How much current does the Epic draw from a car charger or an aftermarket wall charger?
A: It depends...
If the charger has the two data pins (D+ and D-) shorted, the Epic will attempt to draw 600mA. Otherwise, it will draw 380mA.
Q: How can I tell if my phone is charging at 380mA or 600mA?
A: Turn off USB debugging (Home Screen\Settings\Applications\Development\USB debugging).
If you plug into a 380mA source (D+ and D- not shorted), you get a "Charging/Mass Storage/Tethered Mode" popup when you unlock your phone.
If you plug into a 600mA source (D+ and D- shorted), you do not get a popup.
Q: I have a 1A micro USB charger from another phone. Can I use it to charge the Epic?
A: Yes, but you won't get it to charge any faster than the 700mA OEM wall charger. The phone will only draw 600mA at most, regardless of how many amps the charger can supply. (And that assumes that D+ and D- are shorted.)
Q: I have a Palm Pre wall charger. I've heard that it charges the phone faster than the Epic wall charger. Is this true?
A: No. The Palm Pre wall charger does not charge the phone any faster than normal. With my phone hooked up, I measured 590mA (600mA with cable loss). I also saw that the charger had D+ and D- shorted. It behaves exactly like the Epic's charger.
Q: Will these 1A chargers damage my phone?
A: As long as the charger is able to supply the necessary current without overheating, chargers from other phones will not damage the Epic. A charger may be rated for 3A, but the Epic controls how much current it draws.
If you buy a cheap charger, you run the risk of having the charger's chip burn up. Among other things, this could short the charger's input voltage (12V from a car) to the USB V+ line and fry your phone.
Q: I have a USB charger that seems to charge my phone slooooowly. What can I do?
A: Your charger is probably supplying 380mA (or worse). You have a few options:
NOTE: Before doing any of this, make sure that your charger is rated at 700mA or greater. If you have an unmarked charger, chances are that it will not be able to supply 700mA out of the box. Many car charger (such as those for the Nintendo DS) have built-in current limiters that prevent the device from drawing too much current.
1. Modify Your Charger: Open up the charger and look to see if D+ and D- are shorted. (They are the two middle pins on the standard size USB plug.) Modify your charger so that it shorts D+ and D-, and remove any pull-up or pull-down resistors that connect D+ and/or D- to power or ground.
2. Modify A Cable: Slice open a spare micro USB cable (or the cable from your charger), being careful not to damage the red or black wires. Cut the green and white wires (D+ and D-). Strip off a little bit of the insulation from the green and white wires that lead to the micro USB connector. Twist these wires together and wrap in electrical tape.
NOTE: This will prevent the cable from being used as a USB data transfer cable.
3. Buy a USB Charging Cable: Look for a special USB charging cable that already has D+ and D- shorted.
Q: If I buy or make a charging cable, can I get 600mA from a normal (bus-powered) USB port?
A: It depends. The USB spec says that a port can only supply 500mA max. There is usually an overcurrent monitor built into the port that will prevent an overcurrent condition. The OS will pop up a message telling you that you've exceeded the current sourcing capacity of the port.
There are some laptops, however that have ports that allow you to violate the USB spec and draw up to 1A from a port.
Use caution when experimenting.
Q: Can you tell how much current the device draws from the device?
A: No. You CAN, however, get a battery graphing app like Battery Graph.
http://www.appbrain.com/app/battery-...odroid.battery
If you set the monitoring interval to 1 minute and start charging your phone (which should be low on charge) with the wall charger, you'll see a battery curve. You can then repeat this process with your alternate charging method. If you compare the slopes of the charging curves, you'll be able to tell if your alternate charging method is performing the same as your wall charger.
It's not as quick as using a DMM, but it works. It's how I initially saw I was having a problem.
Q: How can you tell if your USB cable has D+/D- shorted?
A: 99% of all cables will not have the lines shorted. You have to buy a "charging cable". But if you are in doubt as to what cable is what, plug it into a PC's USB port. Either the PC will detect the device (not shorted), or you'll trip the USB port's overcurrent mode (shorted).
Or... You can buy a DMM and check the resistance between D+ and D-.
- N

Is there a way to display on the Epic how much current it is drawing? Or some other way to tell if the cable being used is D+/D- shorted?

Thank you. Very helpful.

jasonsf said:
Is there a way to display on the Epic how much current it is drawing? Or some other way to tell if the cable being used is D+/D- shorted?
Click to expand...
Click to collapse
Good questions!
Q: Can you tell how much current the device draws from the device?
A: No. You CAN, however, get a battery graphing app like Battery Graph.
http://www.appbrain.com/app/battery-graph/com.modroid.battery
If you set the monitoring interval to 1 minute and start charging your phone (which should be low on charge) with the wall charger, you'll see a battery curve. You can then repeat this process with your alternate charging method. If you compare the slopes of the charging curves, you'll be able to tell if your alternate charging method is performing the same as your wall charger.
It's not as quick as using a DMM, but it works. It's how I initially saw I was having a problem.
Q: How can you tell if your USB cable has D+/D- shorted?
A: 99% of all cables will not have the lines shorted. You have to buy a "charging cable". But if you are in doubt as to what cable is what, plug it into a PC's USB port. Either the PC will detect the device (not shorted), or you'll trip the USB port's overcurrent mode (shorted).
Or... You can buy a DMM and check the resistance between D+ and D-.

Awesome! Thanks for the info!
Oh, one more thing. Are you saying that the wall charger shorts D+ and D- at the plug? So any cable is essentially shorted when using the wall charger?
Sent from my SPH-D700 using XDA App

jasonsf said:
Awesome! Thanks for the info!
Oh, one more thing. Are you saying that the wall charger shorts D+ and D- at the plug? So any cable is essentially shorted when using the wall charger?
Sent from my SPH-D700 using XDA App
Click to expand...
Click to collapse
You are correct.
For the Epic, the wall charger shorts D+ and D- together.
For wall or car chargers that have a non-removable cable, 99% of the time the short will be inside the charger and NOT in the cable.

Every computer I've used gladly lets me draw 1A without complaints. My old TP was hacked to draw 1A and nothing complained. Didn't even damage the cheapest of the cheap ebay chargers.

Firon said:
Every computer I've used gladly lets me draw 1A without complaints. My old TP was hacked to draw 1A and nothing complained. Didn't even damage the cheapest of the cheap ebay chargers.
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Click to collapse
YMMV. My netbook prevents me from drawing more than 500mA per port.
It all depends on how the USB port circuit is laid out. In the designs I've seen, there's usually a power distribution switch (PDS) in-line with the port that provides overcurrent protection. When that switch trips, it sends a bit to the hub chip that tells the hub that the port is in overcurrent state. (The PDS's secondary function is short-circuit protection. If you stick a car key in your USB port, your computer won't blow up.)
PDS's come in different current cutoff steps, so it is up to the PC manufacturer to choose the right one.
If your PC can't supply the 600mA on a single port to charge the phone, buy one of those USB power splitter cables that lets you draw from 2 ports at once.

I have found that if you plug in the phone and the options for charging, mass storage and tethering pop up, then you are only charging at 380mA. If nothing pops up then you are most likely charging at 600mA.

muyoso said:
I have found that if you plug in the phone and the options for charging, mass storage and tethering pop up, then you are only charging at 380mA. If nothing pops up then you are most likely charging at 600mA.
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Click to collapse
Ding! You are correct. I never noticed because you don't get prompted AT ALL if you have USB debugging turned on.

This is a little off topic. Does the usb cable initiate Dock Mode? I know some other phones use magnets in the dock, but I think I read that the Galaxy S phones detect the car or home dock via the USB cable. Did you discover a mechanism for this in your usb research?

jasonsf said:
This is a little off topic. Does the usb cable initiate Dock Mode? I know some other phones use magnets in the dock, but I think I read that the Galaxy S phones detect the car or home dock via the USB cable. Did you discover a mechanism for this in your usb research?
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Click to collapse
No... I didn't find anything. Maybe I'll "rent" a dock from the Sprint store and find out.

Very nice write up. Answered all the questions I had about the slow charging of this phone. Thanks again.
Sent from my SPH-D700 using XDA App

I am getting substantially faster charges with a 1amp charger than the oem 700, it looks like it is using close to the 1000 ma on some chargers.

aero1 said:
I am getting substantially faster charges with a 1amp charger than the oem 700, it looks like it is using close to the 1000 ma on some chargers.
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Click to collapse
I'll have to pay attention to mine. I started using the 1 amp charger that came with my Touch Pro. I charge it overnight so I don't pay attention to how fast it is charging, but I'll see if I can notice tonight.

aero1 said:
I am getting substantially faster charges with a 1amp charger than the oem 700, it looks like it is using close to the 1000 ma on some chargers.
Click to expand...
Click to collapse
Which chargers? I'll be happy to try any charger that you recommend.

I haven't tested charging by timing the charges, but I have installed a widget that tells me an approximate charge rate called currentwidget, and it gives me the EXACT same values for a 700 ma charger or a 1000 ma charger. Unless this widget is just straight up lying, the phone won't charge any faster than a 700 ma charger no matter how large of a charger you throw at it.

IBNobody said:
2. Modify A Cable: Slice open a spare micro USB cable (or the cable from your charger), being careful not to damage the red or black wires. Cut the green and white wires (D+ and D-). Strip off a little bit of the insulation from the green and white wires that lead to the micro USB connector. Twist these wires together and wrap in electrical tape.
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Click to collapse
I was going to suggest just taping over the data pins in the USB connector (obviously, the regular, non-micro end), but I just tried it and it still popped up the Charging/Mass Storage/Tether, though selecting Mass Storage doesn't work -- the device is not detected by the computer for obvious reasons. I've been using this trick for a while for my mp3 player and my Hero at work and was surprised that it didn't work.

reauxgg said:
I was going to suggest just taping over the data pins in the USB connector (obviously, the regular, non-micro end), but I just tried it and it still popped up the Charging/Mass Storage/Tether, though selecting Mass Storage doesn't work -- the device is not detected by the computer for obvious reasons. I've been using this trick for a while for my mp3 player and my Hero at work and was surprised that it didn't work.
Click to expand...
Click to collapse
No, you need to short those pins together. If you leave them open, it won't go into high-current charge mode.
Those other devices may have had D+ and D- connected across a termination resistor. Putting tape on the pins would have worked then.

IBNobody- I was wondering if you could explain this one- when I plug my epic into the usb port of the cheap charger that came with 2 batteries off of ebay (see here) my epic seems to freeze and the touch screen becomes unresponsive- the charger states it puts out 5.2V 800ma
Could it be that the phone is trying to figure out if its being plugged into a computer vs a simple charger?

[Resolved] Can i charge headphones with higher mA without issues?

I spent much time to research, ask sony support, google... but i dont have answer yet...
I have got: (Everything is 5.0VDC)
Xperia Tablet Z (It comes with 1500mA charger)
MDR1-RBT BT Headphones (It comes with no charger, charge only via USB PC port - 500mA?)
MW600 BT Headset (It comes with 350mA cherger)
Can i charge all with 1500mA charger without ANY issues?
Please help me i can't get answer for long...

Please help.

BUMP

It'll eventually damage it
Sent from my Karbonn A15 using XDA Premium 4 mobile app

Will damage the headphones
Sent from my GT-I9100G using xda app-developers app

arvin07143 said:
Will damage the headphones
Sent from my GT-I9100G using xda app-developers app
Click to expand...
Click to collapse
So i can charge it only via USB to PC?
Sony supporter said i can charge it with adaptor with specs 1500mA...
I don't understand it at all...

BUMP!

This one is not quite so straightforward without knowing about the internal circuitry of those devices you have in regards to how they charge.
Now, in general, it is safe to say that you must always match the voltage and polarity of the device you are charging, often you can use a higher rated current charger or power supply.
Why?
A device typically only draws how many amps it needs in order to function.
Take your TV for example, it probably only needs 2-3 amps to run yet it is plugged straight into the mains which has the capability of supplying many hundred of amps yet your TV doesn't "fry", it simply draws what it needs.
When it comes to charging its a bit more complicated and depends on the device (does it have internal charging circuitry or is the the item you plug into the wall and actual charger and not simply an AC/DC converter).
Most small electronics which contain a battery and are simply supplied with an AC/DC converter, say, Input 120V 1A output 5V 100ma have their own current regulating charging circuitry inside. This means that the thing you plug into the wall isn't actually a charger, its an AC/DC converter.
In that case the converter can have a higher rated amp output than your device states it needs because your device will only draw what it wants.
If what you are plugging into the wall is an actual charger which has the job of regulating the current flow to the device that needs charging then you will want to get one as close to spec as the original so as not to damage your device.
All the devices you list seem to charge via 5V, most likely a USB type interface.
This means that they are not supplied with actual chargers, simply power supplies, the charging and current limiting mechanism is inside each device.
In theory therefore you should be able to 'charge' all your devices via the 1500mA AC/DC converter, the products you have will only draw what they need in order to charge, the 1500mA will not be pushed or forced upon each device.
Also, think of this, you have been smart and come to ask for advice, how many people simply use the USB 'charger' of their husband/wife/sister/brother to charge their phone or product when they can't find their own and those devices aren't damaged.
The only thing is if the current is too low then it will either not charge or take much longer.
I hope that helps.

zasy99 said:
This one is not quite so straightforward without knowing about the internal circuitry of those devices you have in regards to how they charge.
Now, in general, it is safe to say that you must always match the voltage and polarity of the device you are charging, often you can use a higher rated current charger or power supply.
Why?
A device typically only draws how many amps it needs in order to function.
Take your TV for example, it probably only needs 2-3 amps to run yet it is plugged straight into the mains which has the capability of supplying many hundred of amps yet your TV doesn't "fry", it simply draws what it needs.
When it comes to charging its a bit more complicated and depends on the device (does it have internal charging circuitry or is the the item you plug into the wall and actual charger and not simply an AC/DC converter).
Most small electronics which contain a battery and are simply supplied with an AC/DC converter, say, Input 120V 1A output 5V 100ma have their own current regulating charging circuitry inside. This means that the thing you plug into the wall isn't actually a charger, its an AC/DC converter.
In that case the converter can have a higher rated amp output than your device states it needs because your device will only draw what it wants.
If what you are plugging into the wall is an actual charger which has the job of regulating the current flow to the device that needs charging then you will want to get one as close to spec as the original so as not to damage your device.
All the devices you list seem to charge via 5V, most likely a USB type interface.
This means that they are not supplied with actual chargers, simply power supplies, the charging and current limiting mechanism is inside each device.
In theory therefore you should be able to 'charge' all your devices via the 1500mA AC/DC converter, the products you have will only draw what they need in order to charge, the 1500mA will not be pushed or forced upon each device.
Also, think of this, you have been smart and come to ask for advice, how many people simply use the USB 'charger' of their husband/wife/sister/brother to charge their phone or product when they can't find their own and those devices aren't damaged.
The only thing is if the current is too low then it will either not charge or take much longer.
I hope that helps.
Click to expand...
Click to collapse
I know that Xperia tablets and phones won't take more mA than it needs but does MDR1-RBT has the same thing? I did a lot of research but i still can't find the 100% answer. I don't want to try unless 100% sure. (Its expensive headphones)
EDIT:
Few sony supporters said: You can charge it only via USB cabble to Personal computer
Few sony supporters said: You can charge it only via USB cabble to PC or Adaptor (Linked me to USB/AC Adaptor with THE SAME specs like XTZ charger - 1500 mA)
Is Adaptor same as XTZ?
I found this on OFFICIAL Sony eSupport
http://docs.esupport.sony.com/portable/MDR1RBT_guide/en/contents/01/03/01/01.html?search=charg
OFFICIAL TIPS:
Tips
If the micro-USB cable is connected to a computer while the headset is turned on, the headset will be turned off automatically.
To charge the headset from an AC outlet, use USB Charging AC Power Adaptor* (sold separately). For details, refer to the manuals supplied with the USB Charging AC Power Adaptor.
The headset cannot be turned on while charging the battery.
* Refer to the Reference Guide on the recommended adapter.
Click to expand...
Click to collapse

BUMP

Zas99 answer is spot on.once the voltage matches to your device your ok.most phone chargers you can pull out the usb charging cable. u could use that or buy a another usb charger at 1500ma to 2000ma.
Sent from my HTC Desire S using xda premium

E7ite: You should be fine, the fact that it charges via USB means that it must have its own internal charging circuitry.
I bet your Xperia tablet also charges via a USB type cable right, on a USB port?
All my USB 'chargers' have different mA rating yet they charge my products just fine as long as the mA rating is at LEAST what the device needs, not less, and hey, if its a little less it also works, just takes longer.
Look at it this way, the USB specs are always changing as is their current handling capability, now we are at USB 3.1, just recently we were at USB 3.0 which bumped up maximum device current usage during data transmission to 900mA or for dedicated charging 1.5A.
For USB 1.x - 2.0 it was 100mA before negotiation, up to 500mA thereafter, also with a dedicated charging capacity of 1.5A if the D- & D+ pins are shorted.
I bet Sony doesn't tell you that you can only charge via a USB 1.x - 2.0 port do they? Nope, that means if your computer has a USB 3 port that its has the potential to deliver more, remember, that's the key, it CAN deliver more if needed but it won't, it will only give the device what it draws.
The cable they supply with your headphone is most likely not a data cable but rather a so called charging cable so therefore is rated up to 1.5A or 1500mA but your headphones will only draw what they need to charge.
Everyone uses the term charger which is so wrong, when you put your AA or AAA batteries into the little black box and plug it into a wall, that is a charger, when you connect your car battery via the +/- terminals and clamps to the charger, that is also a real charger, they are directly responsible for charging the batteries.
All these other things we use to 'charge' our little electronic devices do nothing other than take the 120V A/C and convert it into for example 5V DC. The current rating they indicate next to the 5V is simply the max current handling capability, nothing more, it not what is pushed to the device, its what the device can request up to to be delivered. The actual charging goes on inside the device.
By the way, as the batteries charge the device reduces the current and sometimes also the voltage, batteries typically charge faster when they are low and able to absorb more current then as they fill up and can absorb less the charger adjusts to a more or less trickle such as 100mA or less in order to maintain but not overcharge the battery.
By the way, this is what I found on Amazon in about 2 minutes, a review from someone else who bought the headphones.
"For the price, sony should have included a wall charger. Instead they included a USB cable. The headphones will charge on any computer, but using a generic USB wall charger will show a blinking amber error light--but the headphones still charge."
Also, the link you indicated to the sony manual about charging gives absolutely no information at all.
You are over thinking it, just try it
If you are really worried why not get a regular cell phone USB charger and use that, one that states like 500mA on it and has a female USB plug on it. That way you can use your headphone USB cable and plug it into the 5V 500mA phone 'charger'.
One last thing, just don't use Apple product 'chargers' to charge non Apple products, why you ask, because Apple does strange things with the pins on their 'chargers' in order to indicate the supply current. This can sometimes lead to adverse effects for non Apple devices.
Good luck.

zasy99 said:
E7ite: You should be fine, the fact that it charges via USB means that it must have its own internal charging circuitry.
I bet your Xperia tablet also charges via a USB type cable right, on a USB port?
All my USB 'chargers' have different mA rating yet they charge my products just fine as long as the mA rating is at LEAST what the device needs, not less, and hey, if its a little less it also works, just takes longer.
Look at it this way, the USB specs are always changing as is their current handling capability, now we are at USB 3.1, just recently we were at USB 3.0 which bumped up maximum device current usage during data transmission to 900mA or for dedicated charging 1.5A.
For USB 1.x - 2.0 it was 100mA before negotiation, up to 500mA thereafter, also with a dedicated charging capacity of 1.5A if the D- & D+ pins are shorted.
I bet Sony doesn't tell you that you can only charge via a USB 1.x - 2.0 port do they? Nope, that means if your computer has a USB 3 port that its has the potential to deliver more, remember, that's the key, it CAN deliver more if needed but it won't, it will only give the device what it draws.
The cable they supply with your headphone is most likely not a data cable but rather a so called charging cable so therefore is rated up to 1.5A or 1500mA but your headphones will only draw what they need to charge.
Everyone uses the term charger which is so wrong, when you put your AA or AAA batteries into the little black box and plug it into a wall, that is a charger, when you connect your car battery via the +/- terminals and clamps to the charger, that is also a real charger, they are directly responsible for charging the batteries.
All these other things we use to 'charge' our little electronic devices do nothing other than take the 120V A/C and convert it into for example 5V DC. The current rating they indicate next to the 5V is simply the max current handling capability, nothing more, it not what is pushed to the device, its what the device can request up to to be delivered. The actual charging goes on inside the device.
By the way, as the batteries charge the device reduces the current and sometimes also the voltage, batteries typically charge faster when they are low and able to absorb more current then as they fill up and can absorb less the charger adjusts to a more or less trickle such as 100mA or less in order to maintain but not overcharge the battery.
By the way, this is what I found on Amazon in about 2 minutes, a review from someone else who bought the headphones.
"For the price, sony should have included a wall charger. Instead they included a USB cable. The headphones will charge on any computer, but using a generic USB wall charger will show a blinking amber error light--but the headphones still charge."
Also, the link you indicated to the sony manual about charging gives absolutely no information at all.
You are over thinking it, just try it
If you are really worried why not get a regular cell phone USB charger and use that, one that states like 500mA on it and has a female USB plug on it. That way you can use your headphone USB cable and plug it into the 5V 500mA phone 'charger'.
One last thing, just don't use Apple product 'chargers' to charge non Apple products, why you ask, because Apple does strange things with the pins on their 'chargers' in order to indicate the supply current. This can sometimes lead to adverse effects for non Apple devices.
Good luck.
Click to expand...
Click to collapse
Thank you for reply.