Related
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.
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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?
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
Hello all. I found some information that some of you may find useful, so I wanted to share.
If you are running a custom kernel, go download Current Widget from the market
https://market.android.com/details?id=com.manor.currentwidget&hl=en
Install it, add the widget to your screen, and plug in your phone. You should be getting 350-380mA, this is AC charging mode. If you are getting in the low 200's you have a charger or cable that is not bypassing the data+ and data- wires in your phone, this is called USB charging.
If it is showing 0mA, then your kernal is not supported and it will not work. You can still do the steps below and get the same results, you will just not be able to see the data visually. I am running Gummy2.0 and the widget works great.
Some chargers are built .. badly.. and rely on a specific cable that will bypass the D+ and D-. the problem is, that cable will not work for anything USB related, such as flashing roms.
If you are anything like me, you have a dozen USB cables laying around and just use the closet one you can find when you need to charge up. However, if you use a data cable with a wall charger that does not disable D+ and D- you will charge at the USB charging rate, which is much slower than when AC charging is enabled, and can be irritating when your phone drains more power than its getting from the charger, resulting in power loss. This happens often while using your phone as a wifi hotspot. In USB charging mode, you can potentially drain the battery faster than the charger can charge. This can be prevented by being in AC charging mode.
You can either dig around for cables and test them out with your charger to see if you can get up to the 380mA range, or you can solder the D+ and D- points together in your charger. I do not recommend the 2nd option unless you are failure with soldering on small IC circuit boards.
But if you are adventurous, the 2 center pins on the USB cable are D+ and D-. If you open up your charger you will see the backside of the USB port and notice the 4 solder points that connect to the USB plug side. Place a bead of solder between this 2 to short them together. This will allow the charger to be in "AC" mode and charge at the higher rate.
This will also work for USB plug car chargers and will allow your phone to continue to have a positive charge even while navigating (which as most people know, Navigating can still drain your battery even when its plugged in).
Hope this helps! Feel free to ask any questions, I will do my best to answer them.
-EDIT-
Make sure to set the update interval in Current Widget to 1, for 1 second updates, this will help when monitoring the charge current.
Let me test this out... I'll report back in a lil bit. Calibrating battery, can't charge. Later...
I'm using a 10' cable from Monoprice. I'm getting 373mA. I'll post on what I get using my car charger... but I'm getting pretty good battery life that I rarely have to charge it in the ride
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 :-/
OK so I need help clearing up some things about charging my phone. I have searched forums and google and I keep finding conflicting responses. I figured XDA may have plenty of knowledgeable people to clear things up. Here is what I think is correct. Please correct me if I'm wrong. I want to find a faster way to charge my phone.
USB data cables (with the exception of some that come from our phone manufacturers) are limited to 500mA because the data pins limit the current that goes through regardless of the rating of the wall adapter.
Example: you have a 1A AC adapter but your phone is only drawing 500mA when charging because you are using a data cable.
Charging cables have the data pins shorted (or missing) and will charge your phone at whatever mA the AC (or DC) adapter is rated at.
Your phone will also have a built in regulator to draw a certain amount of mA's regardless of what the adapter/cable are rated at.
Keeping all these things in mind, I have an AC adapter rated at 5V (standard for these phones) and 2.1A (2100 mA), and my factory samsung micro usb cable that is capable of data transfer as well. Since it is used for data transfer as well I wanted to buy a charging usb cable (with the data pins missing). My theory is this will remove all bottlenecks for charging speed and let the phone's battery pull what it needs, uninhibited by the usb cable and with more than enough current to keep a fast charging rate even when the phone is being used (light usage of course, I dont want to overheat the battery).
If anyone knows about this please clear things up for me, this would make it so much less inconvenient to give my phone a quick charge when needed.
This is my understanding, i might be incorrect:
The 500mA limit doesn't come from the cable but from the mainboard usb specifications.
USB2 can deliver upto 500mA, USB3 upto 900mA.
The different between the "charging" and "data" cables are most likely missing pines, but this has no influence on the current delivered via the cable.
I believe the phones uses the missing connections on a "charge" cable to detect it as charging from an outlet instead of a computer.
I would find it interesting to know if the phones charging routines differ depending on which power source, it thinks, it is connected to.
Probably some typos, but i'm tired ;-).
I guess only thing left to do is buy the usb cable without the data pins and see if it makes a difference. I'll post the results here.
Sent from my rooted GameBoy Color
As Dark3n stated, the limitation is with the USB port capabilities.
Ok you said you want to know the fastest way to charge. The fastest is with the phone off of couse. 2nd. Having a phone in airplane mode will charge fast.
Sent From Space Using My ICS Flavored Sensation
Ohh ok took a while to understand what he meant. Makes sense, thanks all this clears it up
Sent from my rooted GameBoy Color
The fastest method is to have a second battery and an external charger. A battery is much more portable than a charger if you are just out for a day, and if you are traveling, the extra battery & it's charger are not much more bulk than the phone charger alone. I go this route whenever possible as the benefits are inestimable.