Develop Bugs

[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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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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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?
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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.
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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.
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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.
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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.

car charger for KF?

I am looking for reliable car charger for KF. Any suggestions?

It needs to output 1.8v 1.8amps .. which is more than most car adapters will support.

krelvinaz said:
It needs to output 1.8v .. which is more than most car adapters will support.
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So, no car charging? Even slow? I mean, you can charge with 1A, slow but can do a job?

krelvinaz said:
It needs to output 1.8v .. which is more than most car adapters will support.
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I think you are wrong about the 1.8v, my charger says 5v @ 1.8 amps, which means you could use any usb charger rated at over 1.8 amps.

stomp_442 said:
I think you are wrong about the 1.8v, my charger says 5v @ 1.8 amps, which means you could use any usb charger rated at over 1.8 amps.
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Meant to say 1.8amps not volts. Most car adapters are 1amp or less. Many car lighters (the socket) max out at 1amp. Utility plugs may go higher, but the charger plug you use itself needs to support it.

You are right about the 1amp though, anything over 1amp will cost quite a bit more than the few dollars a 1amp adapter costs . In that case it would be worth looking into seeing if the manufacturer of the Kindle Fire sells a car charger, but I would only use that for trips, there is no way I would leave my KF charging in an unattended automobile.

Your best bet would be to find a car charger with a USB port on it that can support an iPad 2. If it can charge an iPad, it can charge the Kindle. Tons of good options on Amazon.

Charge
Wouldnt any cigarette lighter plug with a USB connection work?

schleppy said:
Your best bet would be to find a car charger with a USB port on it that can support an iPad 2. If it can charge an iPad, it can charge the Kindle. Tons of good options on Amazon.
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I bought the "GTMax Black 2-Port USB Car Charger Adapter 2A" from Amazon, it has two usb slots, one with 1A and the other 2.1A. Works great on my Bionic, have yet to try it w/ the kindle though.

I'm using a 2AMP charger as wel and it charges just fine. Most chargers designed for the IPAD will work well. Just make sure it has a regular USB port on it and not the apple connector

Any USB charger with a micro connector will charge it provided the KF is using less power at the time than the charger is able to provide. It doesn't have to be rated for 1.8 amps. I've used everything from a 0.5 amp Motorola RAZR charger to a 2.0 amp charger and they've all done the job. The only difference was the time required. I can't see why it being a car charger would make any difference either. My T-Mobile 1 amp car charger worked just fine with it.

Most USB chargers will work
Hi,
As others have said, most USB chargers will work. However, there is one exception that I ran into recently and its well documented on the forums here - if your battery gets too flat. e.g. you left it at home when you went away, it will need at least 5V @ 1.6A to actually recharge.
Regards

[Q] Can use ipad charger to charge galaxy note?

Hi bringing one charger around would be much convenient. Can i use ipad charger, with 2A output to charge galaxy note?
Tq.

Yes. I've charged mine with it many times.

Hey thanks...

Apple out of norms
Hi
Using a standard USB cable will get you a slow charge, even if the Ipad charger is very powerfull. This is because apple doesn't follow the rules.
Charging your Note may take 6 hours then.
To get fast charge, you need to modify your cable or charger, as stated in this thread : http://forum.xda-developers.com/showthread.php?t=1497864&page=2

jabab said:
Hi
Using a standard USB cable will get you a slow charge, even if the Ipad charger is very powerfull. This is because apple doesn't follow the rules.
Charging your Note may take 6 hours then.
To get fast charge, you need to modify your cable or charger, as stated in this thread : http://forum.xda-developers.com/showthread.php?t=1497864&page=2
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Click to collapse
The increased charge in this mod seems to work for charging via usb port, power from a pc. Charge from main ac lead still higher.
So does charging my Note with an ipad adapter + Note usb cable help increase charge since the ipad adapter has an 2A output??

I'll try to make it clear.
Using a common adapter or any pc USB II or ANY apple adapter will give give you a slow charge with a standard USB to micro-USB 4 wire cable.
This is simply because they can't usually deliver more than 0.5A. For apple, they have a specific standard out of the USB norm.
To go into fast charge mode, the gnote scans pin 2 and 3 of the USB link. If they are short circuited, the gnote tries to go into fast charge mode, and draws up to 1A.
The short circuit of data pins (2 and 3) is specified in the USB norm to state "this adapter can provide 1A"
Some adapters, such as the Samsung one I got with my gnote, already have these pin short circuited inside them and make your phone go into fast charge mode.
If you have an adapter able to supply 1A or more, such as your Ipad's, the simplest way to fast charge your gnote is to have a modified cable. No risk to harm your phone nor your adapter if you respect the wiring.
Sent from my GT-N7000 using Tapatalk

I think i understand now. Thanks so much Jabab.

jabab said:
I'll try to make it clear.
Using a common adapter or any pc USB II or ANY apple adapter will give give you a slow charge with a standard USB to micro-USB 4 wire cable.
This is simply because they can't usually deliver more than 0.5A. For apple, they have a specific standard out of the USB norm.
To go into fast charge mode, the gnote scans pin 2 and 3 of the USB link. If they are short circuited, the gnote tries to go into fast charge mode, and draws up to 1A.
The short circuit of data pins (2 and 3) is specified in the USB norm to state "this adapter can provide 1A"
Some adapters, such as the Samsung one I got with my gnote, already have these pin short circuited inside them and make your phone go into fast charge mode.
If you have an adapter able to supply 1A or more, such as your Ipad's, the simplest way to fast charge your gnote is to have a modified cable. No risk to harm your phone nor your adapter if you respect the wiring.
Click to expand...
Click to collapse
what i want to know is:
if the ipad charger is 2A, will the phone draw all that 2A or just 1A?
im asking because if it designed to work with a 1A charger - is the draw capped at 1A?

Hi
The draw of any phone is limited to its maximum power consumption ie phone consumption + battery charging.
I believe this draw is limited to 1A within the gnote.
Having a 2A charger only means it can provide up to 2A. It's the "pipe" size, in a way.
If there were a way to increase the gnote draw to more than 1A, by example in order to charge the battery faster while using the GPS, this could be :
Either telling the gnote, using a resistor on the 5th pin of the micro-USB plug.
Or using a specific app.
(or both)
I'm not aware of this possibility at the moment.
Sent from my GT-N7000 using Tapatalk

Jabab, thanks for ur valuable expert info. I've notice that charging my gnote with the ipad charger isnt much faster. But charging iphone with ipad charger does gives a great boost. What makes it possible with iphone?

Apple uses a not so different system to tell the iphone or the Ipad that it is connected to a powerful charger: the data pins are connected to the power pins through a ladder of resistances.
I see one main advantage to this: apple could change the resistances values inside the charger to indicate to the device if it is an 1A, 2A or any other current charger.
The main drawback is that this system is compatible with nothing but... Apple devices. This why you get a slow 0.5A charge with a 2A capable Ipad charger.
Sent from my GT-N7000 using Tapatalk

I found the original thread where I learned all this. It may be much clearer than my own explanations.
http://forum.xda-developers.com/showthread.php?t=1384253
I believe though that you need a 1A (1000mA) at least charger to do the indicated mod on the charger for use with a Galaxy Note.
Sent from my GT-N7000 using Tapatalk

I'm Having Charging Issues - Are All Micro USB Cables Created Equally?

I bought an OEM Samsung wall charger that charges at 1 Ampere. I started to charge my Zerolemon battery with it yesterday at about 6pm and here it is today and it is only at about 80% charge rate. Something is not right. I contacted the seller and they told me that the charger is from Samsung and it charges at 1 Ampere. It is either the charger is a knock off or my Micro-usb cable that connects into the wall charger is not the right kind.
Are there different variations of micro-usb cables that will work better? Some that allow more current to flow over them than others? My cable says that it is 28awg/2C. I remember when I had a playstation 3 I had problems with syncing the device with my playstation 3 with the USB cables I had bought. After tons of research it was the USB cables that were the issue. They didn't allow enough current to work properly with the PS3. I'm starting to wonder if I'm having the same issue with the Samsung Wall Charger. Is the 28awg wire gauge too thin?

---->[email protected]<---- said:
I bought an OEM Samsung wall charger that charges at 1 Ampere. I started to charge my Zerolemon battery with it yesterday at about 6pm and here it is today and it is only at about 80% charge rate. Something is not right. I contacted the seller and they told me that the charger is from Samsung and it charges at 1 Ampere. It is either the charger is a knock off or my Micro-usb cable that connects into the wall charger is not the right kind.
Are there different variations of micro-usb cables that will work better? Some that allow more current to flow over them than others? My cable says that it is 28awg/2C. I remember when I had a playstation 3 I had problems with syncing the device with my playstation 3 with the USB cables I had bought. After tons of research it was the USB cables that were the issue. They didn't allow enough current to work properly with the PS3. I'm starting to wonder if I'm having the same issue with the Samsung Wall Charger. Is the 28awg wire gauge too thin?
Click to expand...
Click to collapse
- charger is rated 1amp but usually puts out less depending on the quality and efficiency of it. You won't get the fastest charge with a 1amp psu. Get yourself a cheap 2amp and have plenty of headroom.
- also, if voltage in your wall outlet is low (rare) that would affect psu output.
- yes super thin usb cables can be part of the cause.
- of course, if the cable is meant for PC charging, it will be wired in such a way, to not exceed 450ma (or so) whereas a usb cable or charger that is meant and wired for fast charge, will provide...for me...1150ma (Search/Research my past posts for more detailed info)
- also, most kernels, slow down the charge rate as the batter gets closer to 100% charge.
- a bad battery or custom kernel with bad code, could both affect charging speed.

Slow QI charging

Ordered a QI charger off Amazon (the same Lerway Chinese brand one everyone seems to get) and it's charging incredibly slow. Not sure if the app I'm using to record the charge rate is incorrect or I'm not reading it correctly but it says it's charging at only +200mA max sometimes as slow as <50mA.
Anyone else experience this?

skusa93 said:
Ordered a QI charger off Amazon (the same Lerway Chinese brand one everyone seems to get) and it's charging incredibly slow. Not sure if the app I'm using to record the charge rate is incorrect or I'm not reading it correctly but it says it's charging at only +200mA max sometimes as slow as <50mA.
Anyone else experience this?
Click to expand...
Click to collapse
What kind of power source you use to power the charger and what kind of cable do you use?
If you connect the charger to computer USB port it will not provide enough power for the charger. Same with cheap cables, like the ones mostly included with the generic QI chargers. You need a premium USB cable.
Also if you have a thick case on your phone it will diminish the charging current received by a coil in your phone.
Firstly check how much power and what current your charger gets, so instead of plugging the QI charger, plug your phone and check what amperage you get (I use Current Widget). If it's less then 1600mA (maximum amperage that N5 will allow from direct charging through cable) your charger is underpowered and you need to change socket charger to 2A one. If you're using 2A socket charger and still get under 1600mA then your micro USB cable isn't good enough.
Properly and fully powered Qi charger should charge your bare phone (without a case) at about 700-800mA.

Znamir81 said:
What kind of power source you use to power the charger and what kind of cable do you use?
If you connect the charger to computer USB port it will not provide enough power for the charger. Same with cheap cables, like the ones mostly included with the generic QI chargers. You need a premium USB cable.
Also if you have a thick case on your phone it will diminish the charging current received by a coil in your phone.
Firstly check how much power and what current your charger gets, so instead of plugging the QI charger, plug your phone and check what amperage you get (I use Current Widget). If it's less then 1600mA (maximum amperage that N5 will allow from direct charging through cable) your charger is underpowered and you need to change socket charger to 2A one. If you're using 2A socket charger and still get under 1600mA then your micro USB cable isn't good enough.
Properly and fully powered Qi charger should charge your bare phone (without a case) at about 700-800mA.
Click to expand...
Click to collapse
Thanks for the info I thought I was going crazy.
No case so that isn't an issue.
I have the phone connected direct to a 3A charger currently and am only getting 995mA charge rate with the screen on and it looks like full 1.5A with the screen off. Maybe a defective QI charger?

Nope. Everything is normal. You just need a better cable that will manage to transfer 2A of current.
QI charger needs 2A input to give 1A output on a coil. Giving about 70-80% efficiency rate, your phone would be getting about 700-800mA.
Since your charger gets only about 1A input it gives about 500mA output. Therefore giving that efficiency rate, your phone should be getting about 350-400mA tops. It is possible that your charger has lower efficiency rate (some have about 50-60%), so the values that you're getting are pretty normal unless you use a premium micro usb cable, preferably with thicker, like AWG24 or lower (the lower value the better) power wires.

Might want to try these cables, a lot of people have had great luck with using them on Qi chargers. Don't know which length you would need, they have 3 and 6 foot cables. For the price, I'm ordering 6 6ft cables.
http://www.monoprice.com/Product?c_id=103&cp_id=10303&cs_id=1030307&p_id=9762&seq=1&format=2