Develop Bugs

Which USB cables will allow "fast" charging?

I've been using a mix of old and new USB cables for charging and have noticed that some micro USBs from my Blackberry days will charge the TB but VERY slowly, even using the wall charger.
I want to order some more fast charging USB cables, but how do I identify the difference? What IS the actual difference between the cables?
Thanks!

Usb charging is normally slower than AC wall charging. Most cables are designed exactly the same but some chargers are suited for more amperage per hour. I'd recommend downloading the app -"battery monitor widget" and plugging in your charger and seeing what type of miliamp per hour rating you're getting off of that particular usb port. If the port is in front of the computer, normally those get slightly less voltage than the main ones in the back. Also If you're rooted make sure you aren't on an old outdated kernel that has trickle charge coding thats messed up. I normally get 500-800ma/h based off the AC wall chargers, and anywhere depending on what computer (Work vs Home) USB ports anywhere from like 150-350ma/h. Hope that little tidbit helps.

It is a bit complicted.
When you simply apply power, the Thunderbolt (and most micro USB phone) charges at a slow rate. I have measured this at around 350ma max on the Bolt. This is mainly because the USB port power standard on a PC is 500ma max. They need to stay under that.
By the micro USB standard, if you tie the two USB data lines (D- and D+) together, then the Thunderbolt goes into a fast charge mode. I have seen around 850ma max. You can place a piece of aluminum foil on the charger end (large USB) to short out the two center pins only and switch it to high rate.
Some cables tie the two wires together. Those are fast charge only cables that you can't used for a USB connection. Some chargers tie the two wires together. So they fast charge with any USB cable.
What gets complicated is that of course the charger needs to be capable of about 1 amp for the fast charge to work. AND, some cables use such small wire diameter, that they can't carry the high current rate. I have a couple of cheap cables that even on the fast rate, only carry around 300ma.
AND, if you have time, charge at the low rate. The battery and phone will run cooler, and the battery will last longer. My overnight charger is the lowest rate that I can get by with. But I need to use a super high rate when using the GPS on my motorcycle to keep up with the bright screen and such.

worwig said:
It is a bit complicted.
By the micro USB standard, if you tie the two USB data lines (D- and D+) together, then the Thunderbolt goes into a fast charge mode. I have seen around 850ma max. You can place a piece of aluminum foil on the charger end (large USB) to short out the two center pins only and switch it to high rate.
Click to expand...
Click to collapse
I did this for my CaseMate battery backup and was able to get 800ma charging from it...
If you are just looking for a good car charger, i highly recommend the Motorola Rapid Charger from amazon, they are about $5 shipped. Those charge at the AC "Fast Charge" rate.

converting usb standard to fast-charging
Basically, the cable that came with my tablet, which allowed fast-charging, crapped out. I bought what I thought was the same cable and it still didn't work the right way. In searching through the forums, a a phrase hit me... two-pin fast charging cable. Seeing that, I took a small knife and a pair of needle-nose pliers and extracted the two inner pins( data pins) from he USB side of my cable. The cable, without the data pins, became a dedicated fast-charging cable. I have done this process with three cables so far to see if it was a fluke and every one is capable of fast-charging. I hope anybody that has been hitting the wall on this, reads this, because I was getting very frustrated with the convulated answers some people were giving to address this (especially from Munich!). Try it out, you can bury me in ashes if it doesn't work for you!!!

It's not the cable, it's the brick you're using. My nexus 7 charging brick has a higher output than my tbolt brick, so I use my n7's to charge it in a fraction of the time. Never rely on your computer's usb port to charge your device especially if it's your daily driver

[Q] Rapid Chargers - Not Really Rapid?

i bought that Motorola Rapid Car charger recent and have been using it about a week now. i've noticed that it doesn't seem to charge my Thunderbolt any faster then it did when i was using the Thunderbolt's USB cable with this USB car charger adapter.
so, my question is, why is it called "rapid" if it doesn't charge any faster?
and i suppose secondly, is there an actual microUSB charger that will charge the Thunderbolt faster?
they make one for the iphone that will fully charge it in 30 minutes so i know they are out there.

voxigenboy said:
i bought that Motorola Rapid Car charger recent and have been using it about a week now. i've noticed that it doesn't seem to charge my Thunderbolt any faster then it did when i was using the Thunderbolt's USB cable with this USB car charger adapter.
Click to expand...
Click to collapse
Maybe you should try this one.

Install the battery monitor widget. Monitor the battery for about 20 minutes while charging. Tell us what the charge current is.
Does the Motorola charger include a cable? If not, you may just have a weak cable. I have seen cheap cables with wire so thin that the charging current is no better then charging off a weak USB port.

My experience has been that the phone typically recognizes car charges as USB charging and uses a different charging profile. My solution to that is use a wall charger through an inverter or a kernel that doesn't use radically different charging profiles for A/C and USB.

loonatik78 said:
My experience has been that the phone typically recognizes car charges as USB charging and uses a different charging profile. My solution to that is use a wall charger through an inverter or a kernel that doesn't use radically different charging profiles for A/C and USB.
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Click to collapse
No need for that.
Cut a small piece of aluminum foil. Carefully place it where it shorts the two center conductors in the charger. Plug the USB cable into the charger. Make sure the foil stays in place over the two center conductors.
It is now a high rate charger. (assuming it can put out 1 amp.)

The limiting factor is typically the usb cable itself. Most usb cables can't support the 1amp that is provided to it. Since you used the original usb cable that came with the thunderbolt (that's been "shorted" as mentioned above" ) it will be just as fast as the moto car charger. the 1amp charging rate that the moto charger charges at (i have one) and that the original one charges at are already "rapid". if you plugged a normal usb cable from somewhere else into the other usb car charger, it'd be much much slower

squeakyl said:
The limiting factor is typically the usb cable itself. Most usb cables can't support the 1amp that is provided to it. Since you used the original usb cable that came with the thunderbolt (that's been "shorted" as mentioned above" ) it will be just as fast as the moto car charger. the 1amp charging rate that the moto charger charges at (i have one) and that the original one charges at are already "rapid". if you plugged a normal usb cable from somewhere else into the other usb car charger, it'd be much much slower
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Click to collapse
The stock charger is what shorts the connections. The cable is NOT shorted on the two inner pins because they are the data connections used for connecting your phone to a computer.

doodlebro said:
The stock charger is what shorts the connections. The cable is NOT shorted on the two inner pins because they are the data connections used for connecting your phone to a computer.
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Click to collapse
To meet the USB charging spec (which the TB uses), the two inner (data) contacts should be shorted with no more that 200 ohms.
But, the cable can also be an issue for rapid charging. The voltage drop for a 1A/5V source, across only .5 M of 28 gauge copper is ~220 mV. If you use a longer cable, there's more voltage drop. The TB likely current limits itself when the voltage drops below a certain threshold. Best to buy 24 gauge USB cables, if you can, especially if getting longer ones (monoprice has them).

voxigenboy said:
i bought that Motorola Rapid Car charger recent and have been using it about a week now. i've noticed that it doesn't seem to charge my Thunderbolt any faster then it did when i was using the Thunderbolt's USB cable with this USB car charger adapter.
so, my question is, why is it called "rapid" if it doesn't charge any faster?
Click to expand...
Click to collapse
I think its a matter of rated output current. BUT on the other side, the phone must be capable of drawing/using that much current. If the adapter is rated for more current than the phone can charge, the "extra" current wont be supplied.
Initially, Moto's standard car chargers output 5V and up to 550ma max (just like a standard PC USB port) so they didn't charge phones all that fast. Moto then came out with chargers that had higher current output, so they were capable of charging the phones "faster" than the original car chargers (but on par with the home/travel/AC chargers) and called them "rapid car chargers"..
Today, the current output on the Moto SPN5400A car charger is 0-950mA, and I've seen it sometimes referred to as "Rapid Car charger."
But as far as I know, Moto no longer makes/sells the lower current car chargers, and their web site only shows one MicroUSB and one MiniUSB car charger for sale, both of which appear to be of the 0-950mA output variety.
voxigenboy said:
and i suppose secondly, is there an actual microUSB charger that will charge the Thunderbolt faster?
they make one for the iphone that will fully charge it in 30 minutes so i know they are out there.
Click to expand...
Click to collapse
Just because someone makes such a charger for the iPhone, doesn't mean one must exist for the TB, or other phones, does it? I know the iPad uses a 2A charger. What happens if you connect an iPhone to that? will it charge faster? I guess that depends on if the iPhone is capable of drawing more than 1A to charge it.
I've not seen a "home" or AC charger that can charge the TB any faster than the Stock 1A charger. Does such a thing exist?
A proper car charger with 950mA to 1A output should charge the TB at almost exactly the same rate as the stock 1A wall/AC charger.
And btw, the Moto SPN5400A car charger DOES charge my TB in about the same amount of time that it takes me to charge my TB at home with the stock HTC charger. So while its not "rapid" compared to the stock home/travel/AC charger, its "rapid" compared to PC USB Port charging, or a plain lower current car charger.

KidJoe said:
I've not seen a "home" or AC charger that can charge the TB any faster than the Stock 1A charger. Does such a thing exist?
A proper car charger with 950mA to 1A output should charge the TB at almost exactly the same rate as the stock 1A wall/AC charger.
Click to expand...
Click to collapse
I made a charger for my motorcycle. I use it as a GPS, screen on MAX, phone active with marginal signal. And I wanted to actually charge the battery at the same time. I did a lot of experimenting with the Thunderbolt. It would not exceed a pull of about 850ma from the supply, even at 5.5 volts. IMHO, you are wasting time looking for any charger over 1 amp.
Also, even with about 850ma in, not much over 500ma is getting to the battery. So a totally dead battery is still going to take between 2 and 3 hours to charge, no matter what charger you have. And twice that long if the charger looks like a PC USB port.

worwig said:
I made a charger for my motorcycle. I use it as a GPS, screen on MAX, phone active with marginal signal. And I wanted to actually charge the battery at the same time. I did a lot of experimenting with the Thunderbolt. It would not exceed a pull of about 850ma from the supply, even at 5.5 volts. IMHO, you are wasting time looking for any charger over 1 amp.
Click to expand...
Click to collapse
I was asking because of the OP's statement about knowing "they must exist" because they are out there for the iPhone.
I'm perfectly happy with my Moto car charger, and how fast it charges my phones.

Battery does not charge when the phone is in use!

Hi guys
Im having a weird problem with the battery. It seems battery doesnt charge when im using the phone although it says and shows it charging! It just stays at the same battery percentage it doesnt charge or drain! When i turn off the screen it charges the battery just fine. I called o2 UK where i bought the phone, the rep said when i use the phone it consumes more power than it gets. Can this be true?! Do you think its just a software bug or defective hardware or defective battery?
Sent from my Galaxy Nexus

This is true if you're charging from the USB on your computer. USB ports only provide 500mA. The phone seems to use more than this if you are actively using it. I recommend using a wall plug that provides at last 1 Amp (1000ma) to effectively charge the phone.

How about car chargers? Same thing happens when its charging with the car charger..
Sent from my Galaxy Nexus

If I'm not mistaken, any car charger, whether it's rated at .5A, 1A, or 2.1A is only going to provide .5A to your phone using a typical USB cable. The USB cable that came with your phone has +/- lines for power as well as 2 data lines. If you pickup a "charging only USB cable" it has the data lines shorted so that only the power lines are functional. This type of cable would allow you to take advantage of the higher current 1A and 2.1A chargers - I think anyway. I'm still new to Nexus so I haven't confirmed that, but that's the way it worked on my old phone. I did read somewhere that even with a charging only cable someone wasn't able to pull 1A from their car charger so I don't know if that was a unique issue or if the Nexus doesn't behave the same way. My understanding is the amount of current pulled from the charger is dependent on the charger AND the phone. Using a special charging cable tricks the phone into thinking it's on A/C I guess.

Highest Charging Current for One X

Hi all:
I just did a test on the maximum charging current of the One X using current measurement equipment, and it shows that the One X does not draw above 460mA of current while charging.
With this value, i suspect that the One X limits max charging current at 500mA, which means 3 things:
1) Using any previous generation USB charger (750mA or 850mA or 1A) is good enough. Attempting to use the iPad's charger (rated at 2A) WILL NOT get you faster charging time.
2) When using battery draining applications, the charging current may not be enough for you to both CHARGE and USE the Phone. Thus it might be a better idea to give your One X some dedicated charging time.
3) Some computer USB ports may specify 500mA of output current, but there are many times the available current is less than that. On my USB port, the charging current is only about 300mA at times. So it is better to use a dedicated charger if you have it available. Having that said, however, it is still ok to charge the One X with a USB port at 300mA, just that charging will take longer.
That's all I have to report. Useful information for all.

limestone said:
Useful information for all.
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Click to collapse
Useful indeed. Thanks
Sent from my HTC Vivid using XDA app

I've had mine charge at 780mAh+ before. 1amp HTC charger. Charge rate slows down at the last 20-30% or so. So from 70%-100% battery, charge rates normally slow to about 450mAh.

limestone said:
Hi all:
1) Using any previous generation USB charger (750mA or 850mA or 1A) is good enough. Attempting to use the iPad's charger (rated at 2A) WILL NOT get you faster charging time.
Useful information for all.
Click to expand...
Click to collapse
thanks a lot, i can confirm the statement above because my stock charger is broken and i'm using the ipad's one.
bye

i tried to use the charger for htc chacha and hd2..
both does not work.. red light will light up but after a while it will go off and the phone does not charge..

Charging my HOX while the phones working hard eventually (after say, 5 mins), causes the charge LED to flash green/red. I've had this twice now, once while playing a 720P HD film, and once when playing Glowball.
Both times the phone was very hot, so i'm not sure if the LED thing was to indicate that the battery was too hot to charge, or that the charger could not supply enough power to charge and power the phone at the same time.

fi3ry_icy said:
i tried to use the charger for htc chacha and hd2..
both does not work.. red light will light up but after a while it will go off and the phone does not charge..
Click to expand...
Click to collapse
I'm using my HD2 charger at work every day. It charges at about 400/500mA.
Original charger gives me 650/750mA (lowers at the end)

chaps said:
Charging my HOX while the phones working hard eventually (after say, 5 mins), causes the charge LED to flash green/red. I've had this twice now, once while playing a 720P HD film, and once when playing Glowball.
Both times the phone was very hot, so i'm not sure if the LED thing was to indicate that the battery was too hot to charge, or that the charger could not supply enough power to charge and power the phone at the same time.
Click to expand...
Click to collapse
If the charger cannot cope with the discharge from the game, a pop up message actually appears. If it's blinking means it's too hot. Try not to do anything intensive the last 20-30% remaining (meaning at 70-100% battery).

Nice info thanks
Sent from my HTC One X using XDA

fi3ry_icy said:
i tried to use the charger for htc chacha and hd2..
both does not work.. red light will light up but after a while it will go off and the phone does not charge..
Click to expand...
Click to collapse
Same here... I am using the Atrix 4G (US) charger, it does not charge the phone. The charger gives output of 850mA. It does charge when plugged into the laptop, but I think it will take very long that way.
*edit for posterity*
after a while (I did it when battery had charged to 20%), I could connect the Moto US charger, and it would show as "AC". It would not want to charge through it when the battery was really low (2%), but it would charge via USB in that case. Weird behavior, IMO.

USB limited to 500. AC limited to 1A.
Sent from my HTC One X using xda premium

If you want maximum speed of charging (AC charging) you need:
1A charger with shorted D+ and D- pins (eg, original HTC charger).
iPad charger probably doesn't have these pins shorted, so in this case phone will see it as USB charging (you can check it in settings->battery) and will limit charging current to 500mA. Also lot of aftermarket car chargers will work only in USB mode despite they are able to supply 1A.
Here you can find some info on USB Charging Ports (shorted D+- pins):
http://en.wikipedia.org/wiki/Universal_Serial_Bus#Charging_ports_and_accessory_charging_adapters

When charger is "USB", it will not draw more than 500mA from the charger, and usually it will not charge at all (because the current draw with screen on is higher than 500mA).
When charger is AC, it seems to draw 1000mA - but this is still too low to charge while phone is doing anything, as it will draw 700mA and charge ~250mA top.
I hope this can be tuned in kernel, because it sucks, I also hope that power source can be AC (and not battery - look in dmesg when charger is connected), because battery gets too hot when under load...

colin_ktp said:
If you want maximum speed of charging (AC charging) you need:
1A charger with shorted D+ and D- pins (eg, original HTC charger).
iPad charger probably doesn't have these pins shorted, so in this case phone will see it as USB charging (you can check it in settings->battery) and will limit charging current to 500mA. Also lot of aftermarket car chargers will work only in USB mode despite they are able to supply 1A.
Here you can find some info on USB Charging Ports (shorted D+- pins):
http://en.wikipedia.org/wiki/Universal_Serial_Bus#Charging_ports_and_accessory_charging_adapters
Click to expand...
Click to collapse
Can you post a potential list of car charger which are working at 1mA according to you?

I've only tested few devices:
Extrememac external battery for iPhone/iPad (max 2A) had pins not shorted - USB charging mode on One X (500mA).
Some cheap car adapters - max 1A (according to spec) - USB charging mode on One X.
To fox this problem you should prepare a USB extension cable or micro-usb cable with shorted D+ and D- pins and it should be recognized as AC adapter. I think that also some old HTC phone chargers might come with shorted pins in cable already, but don't know which...

What about the official HTC car charger?

MickyMax said:
What about the official HTC car charger?
Click to expand...
Click to collapse
Yes, that one will charge at the full rate.
There is no list of known good chargers - it's down to luck or a recommendation from someone who found one. You can be sure that any charger advertised as "iPhone, iPad or iPod" compatible will NOT charge your One X at the full rate.
I found one recently in a local petrol station shop. It was £5. I took it apart to have a look and the D+ and D- pins are correctly connected together (via a low value resistor) so it charges at the full rate.
So, I might suggest you look for the cheapest Chinese car charger you can.

USB charging not OK inside a car
zvieratko said:
When charger is "USB", it will not draw more than 500mA from the charger, and usually it will not charge at all (because the current draw with screen on is higher than 500mA).
When charger is AC, it seems to draw 1000mA - but this is still too low to charge while phone is doing anything, as it will draw 700mA and charge ~250mA top.
I hope this can be tuned in kernel, because it sucks, I also hope that power source can be AC (and not battery - look in dmesg when charger is connected), because battery gets too hot when under load...
Click to expand...
Click to collapse
Bingo. I also noticed that when I have the screen on at 100% brightness, GPS and Bluetooth on, i.e. in the car, the USB charger cannot even keep up with the battery drain.
On top of that, the battery gets really hot.
I did not have any of these issues with my SGS2, and frankly, I think it's very disappointing. One should at least be able to stay on the same battery level while doing nothing too fancy and on USB inside a car.

A380 said:
Bingo. I also noticed that when I have the screen on at 100% brightness, GPS and Bluetooth on, i.e. in the car, the USB charger cannot even keep up with the battery drain.
On top of that, the battery gets really hot.
I did not have any of these issues with my SGS2, and frankly, I think it's very disappointing. One should at least be able to stay on the same battery level while doing nothing too fancy and on USB inside a car.
Click to expand...
Click to collapse
There are a lot of factors in the charging current. When you charge, the battery will heat up during the process, especially towards the end of the charging cycle. If you are using your phone at the same time and cause even more heat and charging may slow down to prevent overheating. Also, as mentioned prior, charging slows down as capacity is reached. 100% brightness, GPS, and Bluetooth all on has always walked the fine line of just barely keeping up on my past phones on a 500 mA USB charger. On top of that, this phone is a lot more powerful than an SGS2 and the T3 and big screen produce more heat which may be slowing your charging more.
The problem is a lot of cheap chargers that the phone thinks are USB chargers, not AC chargers, thus causing them to only charge at 500 mA. If you have a proper charger, or a properly modified charger, you should get more like 1A, assuming conditions are right.
In the past I've used Battery Monitor Widget from the Play store to show my charging current on a widget, as well as track and graph battery use, charging current, temperature, etc. Might want to give it a try if you're more interested in charging details.

Im using my htc desire charger and cable (the one that splits in two). It works fine for me but it does take a while to get a full charge. Should i use the charger and cable that came with the phone?

Car Tablet Install Not Charging Consistently.

As the title I'm having problems charging. A lot of the time the battery is discharging and requires being charged inside, where it does charge consistent and fast!
I the car I have a 10amp 5v dc/dc converter providing the power, I have the thick cable OTG from amazon, along with Amazon basic USB cable extensions, and a 4 port hub.
I've used different chargers, even dual chargers with a USB hub that had independent power, I changed the OTG cable, Heck I even changed TABLETS! From a Wi-Fi to an LTE. The only common thread is the backup camera and Timur's kernel.
Considering it charges perfectly plugged into a wall I assume it's not the kernel.
I've seen at least one other with this issue, Any ideas? I've been playing with this for months and as mentioned have changed every aspect of the install except the camera.

fr4nk1yn said:
As the title I'm having problems charging. A lot of the time the battery is discharging and requires being charged inside, where it does charge consistent and fast! I the car I have a 10amp 5v dc/dc converter providing the power, ...
Click to expand...
Click to collapse
These car chargers supply perfect 5.0V while your original Asus AC charger delivers 5.2V (have a look at its specs). Believe it or not, 0.2V makes the difference, and at 5.0V your tablet will not charge reliably. I actually use a regulated PSU set higher, at 5.3V, to compensate for voltage drop on poor USB cables.
Look for 5.2V/2A car charger and use max 1m quality USB cable, no hubs.

Thanks. The charger is indeed 5.2v. Odd. What charger are you using?
This is the one I have: https://www.amazon.com/Converter-Re...1513386282&sr=8-8&keywords=dc+to+dc+converter and it puts out 5.1v
I found it was only getting 8v-10.5v and wired it directly to the car's wiring, I was using spades previously to connct to the Aux power connector, Getting full 14.2v made no difference to the tablet's charging.
Next I removed the tablet and plugged it into a 5v/2amp wall charger using the old OTG and the old 3 foot USB extension cable. It charges consistently between 580 - 740mA. Meanwhile it went dead installed in the dash, again.

fr4nk1yn said:
This is the one I have: https://www.amazon.com/Converter-Re...1513386282&sr=8-8&keywords=dc+to+dc+converter and it puts out 5.1v.... Meanwhile it went dead installed in the dash, again.
Click to expand...
Click to collapse
To diagnose this problem you will have to acquire a simple, cheap USB meter and connect it as close as possible to N7. Note on the attachment my N7, 15cm USB cable and a tester measuring 5.18V. Please post your voltage reading.

I bought a 3amp adjustable DC to DC converter.
Set the voltage to 5.3v initially, then measured at the end of my 1 meter USB extension cable. It was still 5.3 so I dropped it back to 5.2v.
Plugged the tablet in, and it's immediately discharging at 563mAh. No apparent change after some use.

Thanks @k23m for the help. This thing just deteriorated. Something pulling a huge amount of power too. Sucked a fully charged battery to 0 in a day of of running errands. And it was sluggish beyond belief. I thought the ROM might be corrupt.
So I did the battery removal mod. It's working great on the bench so it's being wired up tomorrow. Thanks again.