So I have noticed that charging via the USB cable to my computer takes much longer than charging via the USB cable to the wall-wart (not so much of a wart on this device ).
I understand the differences between trickle-charge and regular-charge (I think), but how does the phone know which source is charging it? When it's plugged into a laptop/desktop, I know it would communicate differently than just recieving a voltage. If it's in charge-only mode, then it shouldn't matter, right?
wall charger puts out more amps
google says usb port puts out 200-500 ma. the factory htc wall charger says 1.0 a or 1000 ma
headcheese said:
wall charger puts out more amps
google says usb port puts out 200-500 ma. the factory htc wall charger says 1.0 a or 1000 ma
Click to expand...
Click to collapse
Hmm. I find that very interesting. I have seen some older external HDs that had two USB connectors on the same line (one labeled Power, the other labeled Data). I wonder if there would be a way to up the power output of my Notebook/Desktop USB.
When I'm at work I don't have access to a power outlet at my terminal, but I can plug my phone into the front USB port of the desktop here (as long as I don't get caught plugging in external peripherals ).
nerozehl said:
Hmm. I find that very interesting. I have seen some older external HDs that had two USB connectors on the same line (one labeled Power, the other labeled Data). I wonder if there would be a way to up the power output of my Notebook/Desktop USB.
When I'm at work I don't have access to a power outlet at my terminal, but I can plug my phone into the front USB port of the desktop here (as long as I don't get caught plugging in external peripherals ).
Click to expand...
Click to collapse
some hdd will consume more power than just the single usb port and requires two... as for upping the mA raiting, it wont happen because usb is limited to 500 mA like previously mention, unless you have a external usb hub spitting out power
I'm sorry I misunderstood you before: I didn't interpret that as having meant that 500mA was the upper limit. Maybe a cable could be rigged to double that by using two connectors?
nerozehl said:
I'm sorry I misunderstood you before: I didn't interpret that as having meant that 500mA was the upper limit. Maybe a cable could be rigged to double that by using two connectors?
Click to expand...
Click to collapse
think of it like a backup and lighten the load your device takes, in this case a external hdd. Idle is uses less power, but when it spins up and starts reading it might need that burst and constant voltage errm i shouldnt say voltage..i meant amps(milliamps in this case)
Perhaps I should have done some more Googling before I started this thread, but to anyone who is curious, I found some cool information here: http://www.girr.org/mac_stuff/usb_stuff.html
Related
Hi,
I can't find the answer anywhere, but anybody knows how long it takes to full charge the Nexus from below 10% using the Desktop dock ? With the bluetooth component taking some power, I am guessing that it should be slower than the wall charger but faster than via USB ?
Alternatively, what does it say under Battery info when dialing *#*#4636#*#* when it is hook to the dock ? Does it say "Power plug" or "USB" or something else like "Dock" ?
The more I think I about it, the more I think there are probably more than two modes of charging for the Nexus, either USB ( 500mA ), Power Plug ( 1A ) or something inbetween for the dock ?
If this third mode does exists, I wonder how much current it draws and if this third mode only available via the dock pins. I am interest as I would like to build a cable similar to those old portable hard disks where they take two USB plugs and connect the power in parallel to provide more than 500mA. I doubt I would really get the full 1A out of motherboard but sure hope to be more than 500mA. The question is would the Nexus take advantage that to make cutting those cables worthwhile.
Thanks
Ted
There is no third method. Charging via dock is no different from charing directly - it's either USB or AC, depending on the power supply you attach the dock to.
Please note: the manual says to NOT attach the dock to a computer USB port!
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.
Click to expand...
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.
Click to expand...
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?
Click to expand...
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.
Click to expand...
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.
Click to expand...
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?
(Yes I mention android development but this is regarding a 'general' topic)
As an android app developer, it's pretty much mandatory that I have my devices plugged into the computer for ADB. However, with wifi / bluetooth / GPS / screen brightness turned on or cranked up, I also need to have the device plugged into something that provides more than the measly 500mA that the computer's USB port can provide. From what I've been able to gather, the USB standard requires that USB hubs and ports cannot supply more than 500mA to a connected device. However, I suspect that there are manufacturers out there that are aware of the need for simultaneous charging + connectivity and have made special cables specifically for this (What I'm thinking of is a Y usb cable where one end plugs into the device, one plugs into the computer and only uses the data wires, and the other plugs into the charger which feeds and charges the device.) Do any of you know if something like this exists and where I can find one? I've definitely tried to Google for it but the phrases I'm using are long and not producing the right results. I obviously don't know the correct term(s) to search for.
If I knew a bit more about circuitry in general and the USB standard specifically, I could probably solder together a cable like this with a couple diodes to prevent the charger from zapping the motherboard's USB, or perhaps, as mentioned, not connect the power wires at all. I do have 6-8 spare cables laying around but I'd rather not start chopping and black-taping unless I get some confirmation Plus I only have one female end to mangle, so... yeah ;p
My idea for the splice & solder (in case no commercially available alternative exists):
Code:
computer - 2 data -----\
|----------------- device
charger - 2 power -----/
Most chargers and phones have some kind of regulator circuit built-in anyway, at least that's the impression I'm under. Generally if you crack open a charger there are only two cables black and red (+/-) which makes things considerably easier but that's assuming you have a charger that's just for charging and not one that requires you already have a usb cable to plug into it (like some that come with phones now). Standard wiring color schemes applied to all the cables I've cut open and spliced so as long as you go black/black red/red from the charger and leave the other wires untouched you should be ok. You'll know if something's wrong quickly because your phone will get quite a bit hotter than normal and do so faster, and you shouldn't need to add any components as they're already in the charger circuit (diodes to prevent current flow-back, resistors and the transformer to convert to dc, capacitors to smooth the current, etc). Just use common sense when working with this, don't solder until you test, don't splice wires together that don't seem right, use a multimeter to make sure you're getting the proper wires, don't work on anything while it's live unless you're properly insulated and even then not if you can help it, all that jazz.
Yeah, my biggest concern would be that I was told that some USB devices negotiate current requirements with the motherboard, which I'd assume goes over the two data wires, but I remember landline phones have 2 wires but both power and data flow over it, so I wasn't completely confident that the two power wires weren't passing data as well. If I run the 2 data to the computer and the 2 power to the charger, and it turns out that the negotiation requires all 4 wires be connected from the device to the computer, then I've just ruined two good cables.
I just am not so super confident in my logic and theorizing that I'd want to risk frying circuitry If I can nab a commercially available accessory that does this for $30 it's a lot less than having to buy another $700 device and a new $200 motherboard (at the least)
I don't think you really have to worry, but I wouldn't replace the charger wires, I'd connect the wires from the charger to the power lines inside the usb cable that way even when the charger isn't plugged in the phone is still getting some power and it'd basically be hooking them up in parallel when the usb and charger are plugged in. You could always go buy a $20/$30 cheapo phone that connects through microusb-to-usb and test the cable on that through a USB hub. that way if something goes wrong you're only losing a cheapo phone and a usb hub, but honestly things shouldn't fry as long as you get the wiring right and don't try to do something like black to red because then you're feeding power from the charger back into the usb socket which is where things get ugly.
I think i've found something on the interwebs, that will actually save you the wire-splicing and soldering
It is actually just what you described, it uses 2 USB ports in order to provide 1000mA to a device.
dealextreme.com/p/cable-style-dual-power-1000ma-usb-2-0-4-port-hub-13526
Sorry for the inconvience with the url, atm i'm not yet allowed to post links directly... :/
Xadro said:
I think i've found something on the interwebs, that will actually save you the wire-splicing and soldering
It is actually just what you described, it uses 2 USB ports in order to provide 1000mA to a device.
dealextreme.com/p/cable-style-dual-power-1000ma-usb-2-0-4-port-hub-13526
Sorry for the inconvience with the url, atm i'm not yet allowed to post links directly... :/
Click to expand...
Click to collapse
I know that some of the smaller usb external drives have a cable that has 2 "type-a" connectorsto allow data connection/enough power for the drive. I have not seen these in micro-usb form, only mini-usb. SO, I do not see why it would not work.
papabear said:
I know that some of the smaller usb external drives have a cable that has 2 "type-a" connectorsto allow data connection/enough power for the drive. I have not seen these in micro-usb form, only mini-usb. SO, I do not see why it would not work.
Click to expand...
Click to collapse
Agreed, USB offers about 2.5v of charge aswell as data connectivity of course, I don't understand why it wouldn't work... I can tell you from experence through that it does take about 40% longer, and will suck the life out of a laptop if you are using it on battery mode.
The reason I was thinking about cutting the power wires from the computer entirely is I don't know what dumping 1-2 amps into the computer's USB port is going to do ;p
Edit: Looks like newegg.com/Product/Product.aspx?Item=N82E16817707145&cm_re=2a_output_usb-_-17-707-145-_-Product should do what I'm interested in, if the details are legitimate. Who knew finding a hub with full details would be so hard? ><
LycaonX said:
The reason I was thinking about cutting the power wires from the computer entirely is I don't know what dumping 1-2 amps into the computer's USB port is going to do ;p
Edit: Looks like newegg.com/Product/Product.aspx?Item=N82E16817707145&cm_re=2a_output_usb-_-17-707-145-_-Product should do what I'm interested in, if the details are legitimate. Who knew finding a hub with full details would be so hard? ><
Click to expand...
Click to collapse
just as papabear already said, there are also external hdd, that use this kind of wire.. so it should be no problem. If the ports arent't capable of delivering that power (but as far as i know they are designed for 500mA each), simply you will not get the the full 1 A.
And i must agree, hardware vendors rarely add detailed power info -.-
Currently using BuoyAOSPsy v131 ROM
I have noticed that my battery still drains while I am plugged in and the phone indicates it is plugged in. Have not tested this while plugged into a wall jack, only in my car or via USB to computer.
When this occurs I am using GPS/Navigation software, active data connection (ofc), and playing music.
Does USB or car adapter not supply enough "juice" for this phone to run multiple applications/features? Is there anything I can do to remedy this, such as try a different car adapter? What specs do I need to look for to ensure appropriate power transfer?
Thanks!
**@ Moderators: Hopefully I placed this in the correct forum. Since it is not necessarily directly related to the ROM I thought it should be kept out of the ROM's thread.
Yes you can easily draw more power then its supplying when using computer or car charger. Most of the time its only charging 500 ma when charging that method. Wall charger's I believe are 1000 ma. Navagation is a HUGE draw on battery.
u921333 said:
Yes you can easily draw more power then its supplying when using computer or car charger. Most of the time its only charging 500 ma when charging that method. Wall charger's I believe are 1000 ma. Navagation is a HUGE draw on battery.
Click to expand...
Click to collapse
Thank you for the info. Guess I'll just have to find a higher quality car adapter.
Actually ive read when using a data cable ie stock or regular micro usb cable on a usb port on your pc or a regular charger the max it will get is 500ma. one of the oem wall chargers (block with usb port) is able to supply 1000ma and the phone is only able to sense this the data pin + and - are shorted together. this tells the phone its charging ac plugged vs usb. now check the output of your car charger and if its able to supply more than 500ma then you can either short pins 2-3 on your cable or on your charger and you will get maximum current draw. Research it you ill there was an article posted on xda somwhere.
I'm getting 1000ma from both my ccar charger and AC adapter. u don't want to pin short a cable and charge from usb. drawing that much power will damage the port, it wasn't designed for that (1.0,2.0). USB 3.0, on the other hand :-D
Anyone wanting to know how to fast charge using the usb port on your pc/laptop?
This usually takes ages compared to charging via mains lead, the hack itself is quite simple and involves modifying the usb cable
my results are as follows (these can vary depending on what you are using your phone for, what background apps running, etc.
charging with mains lead :
4.2v
998mah
mains ac
charging with STANDARD usb lead:
422mah
3.999v
standard usb
and finally the MODIFIED usb lead hack:
4.161v
782mah
usb hack
as you can see it is a 53% increase in charging compared to standard usb charging mah, and slightly under mains ac charging mah,
as my phone is always plugged in at my work pc or home pc or laptop or whatever this works out good
TUT:
use at your own risk this is for information purposes only and I hold no responsibility to any damage that may arise
using a micro usb cable (charging cable for htc phones)
cut it using a pliers half way through the cable
using pliers again cut away the thick black wiring, the red and black small wiring, and white and green wiring
from the usb port end to the microusb connect the black and red cables together so they join
from the microusb end short out the white and green cables together
from the usb port end leave the white and green cables, do not touch these
use insulation tape/solder to clean it up and then your cable is ready
I will make a mod for car chargers also soon
see attached image showing which wires to cut and which to join up and which to leave alone, if this helped you in anyway (it should help you ) then please hit the thanks button
this mod will trick your pc/laptop/htc into thinking that it is not a pc usb cable and will allow higher currents and voltage to your phone
you can check this with current widget from market place
once this mod is done, you cannot use the same cable again for pc/usb tethering or usb disk drive, only cable can be used for charging
Care to explain how you did it? I got a spare Micro USB cable willing to try and make a tutorial with pictures.
So you forgot to put the directions for the mod...
Sent from my Sensation 4g using XDA App
directions are up with a picture
Seems awesome, but I'd be way too scared to try that on my own. >.<
First of all im not against this mod. Just want to share my experience just this morning.
I charge my phone via the stock usb cable to my pc and leave until morning approx 7hrs. What happen now my phone Menu button become unresponsive tried different method, shake google for answer , but nothing work. Worst come to worse i may return the phone to HTC for repair. So for anyone want to try this be careful, this could be a problem with HTC as it could result more problem.
HTH
Sounds dangerous and a bit risky. Why not just use a USB y cable and a micro USB adapter?
http://item.mobileweb.ebay.com.au/viewitem?itemId=370586078337
Its not dangerous nor risky in my opinion...
I am using this trick since I owned HTC TYTN2 and I`m using it now.
Hmmm...
I always thought the different voltages came from the charging adaptor..
The phone adaptors have normal charging voltages so thats why charge normal speed... however PCs have lesser voltage due to USB ports. I think the PC voltage varies on the device that's plugged in.
Thus, we can use the same cable for charging with an adaptor and also for data transfer and the phone knows what its plugged into.
Pardon me if i'm wrong... could be a misconception i had
Why go to that bother when you can just plug in the adaptor!
Sent from my Sensation using Tapatalk
thunderskain said:
Hmmm...
I always thought the different voltages came from the charging adaptor..
The phone adaptors have normal charging voltages so thats why charge normal speed... however PCs have lesser voltage due to USB ports. I think the PC voltage varies on the device that's plugged in.
Thus, we can use the same cable for charging with an adaptor and also for data transfer and the phone knows what its plugged into.
Pardon me if i'm wrong... could be a misconception i had
Click to expand...
Click to collapse
It's got nothing to do with the voltages, they are the same. The phone senses that the data wires are not connected together (open) and presumes that it is plugged into a pc / laptop usb port. Because of this the phone then restricts the current it draws from it's source so that it doesn't cause damage to the pc / laptop usb power supply.
Inside the phone charger the data connections will be shorted out so the phone knows it's the charger and can draw full current.
There is a chance that it could damage the pc / laptop if the usb port supply is not rated high enough
Just to update the thread, I've been using this for the last year and a half on all the HTC's I own and no issue at all,
I can connect my phone to my laptop if i dont have access to mains
I can use the cable in the car to a usb charger (which charge slow for some reason)
there are many reasons i.e. in work where I can only use a usb port and no extra plugs for a/c, it means I don't have to carry a plug around with me just a usb cable,
A good post, the issues around drawing to much power could effect older laptops
If I understand correctlly USB3 has the ability to supply more power than USB 2
Anyone any idea if this would reduce charge times without the mod?
battery will die soon enough...
you should place a 220 Ohm resistor between the data lines (green and white) if you do that, you will be able to use the where it was intended for, data
with the 200~220 Ohm resistor the phone recognizes the connection as AC-charger. i dit this with a DealExtreme carcharger
source: http://www.ifixit.com/Guide/Upgradi...-current-to-HTC-Hero-and-other-devices/5172/1
If you can get to the ID-pin of the USB-connector (pin4) and connect the following resistors to GND, you get interesting USB modes
Dock-mode = 44-49 kOhms
Car-dock = 5-16 kOhms
source: http://forum.xda-developers.com/showthread.php?t=1185431
I've done this, and soldered all the cables in the right positions, now I'm testing the charge times between this and a normal usb cable on my HTC G1.
First thing I noticed was that my phone says charging via AC, instead of usb.
Will edit this with the results.
Edit : Been a while, forgot about this, so I forget the exact numbers, but my phone charged around 1 and half hours faster with this mod, and yes, it was on USB 3.0 so its quite good.
Worthless to try if you don't have USB 3.0.
Sent from my GT-I9100 using xda premium
Does this mod increase charge with main AC lead that output 2A e.g. Ipad charger head???
usb3 provides up to 900ma
so usb3 should work without any problems
this is usb specification
http://www.usr.com/education/peripherals0.asp
by default usb2 provides 500ma unless it is asked for more by the device, this is where the mod of the cable comes into play, it provides up to 1000ma with this mod
johnerz said:
If I understand correctlly USB3 has the ability to supply more power than USB 2
Anyone any idea if this would reduce charge times without the mod?
Click to expand...
Click to collapse
I have an Notebook with USB3.0 and also Power-USB. (Power usb only works with a dockingstation).
The charging is also bad. Takes about ~4 hours from 2% - 100%.
I thought about power reducement by phone, when dataconnection is available. Now I know it for sure :-/