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It seems the only way to fast charge a N1 is with the supplied wall charger. Standard Micro USB chargers whould only allow at much as 450mA of charge current regardless of the adapter current capacity.
The bundled charger however, manages to push 900mA into the N1. I made a cut in the charger wires and measured the current draw to make sure.
Now.. I'd like my car charger to be able to do the same. There must be some hack in the plug of the N1 charger since there are only 2 conductors from the case to the plug. You can see that the plug is somewhat longer than similar Micro USB plugs..
So I tried to see if one of the 3 unused pins can tell me anything but.. they seem unconnected as far as I could tell. Diode measurement (to test for any digital part inside) also did not produce any results. The next obvious step is to take the molded plug apart but I'd rather not...
Does anyone have any clue as to what makes that plug so special?
And please - I did my tests with a bench power supply - not the car chargers - so don't go around telling me it has to do with charger current capacity.
Thanks,
Nir
are you sure the micro usb cords you are using are able to handle the amps? most chargers made prior to now, only push about 450mA, the G1, and N1 chargers i have push a full amp though. I just ordered a car charger that pushes an amp too. There is nothing "special" about the plug.
followinginsanity said:
are you sure the micro usb cords you are using are able to handle the amps? most chargers made prior to now, only push about 450mA, the G1, and N1 chargers i have push a full amp though. I just ordered a car charger that pushes an amp too. There is nothing "special" about the plug.
Click to expand...
Click to collapse
I beg to differ. All the cords can easily supply 1 AMP. It is the phone itself that decides how much to draw from the charger based on something IN THE PLUG.
I am an electronics engineer so do understand I know perfectly what I am talking about
And your 1A car charger does not supply anything over 0.45A to the phone.. you will see that if you are using the phone while it charges (say nav or phone call) the phone actually looses some charge albeit it being charged... This will not happen with the stock wall charger.
I have a 900mAh car charger that I use and it does in fact give 900mAh to the phone while charging. I can tell because I used a 450mAh charger at home before and it was slooow and I could drain my phone while charging it. With the car charger I can stream music with spotify, use the GPS, have the screen on full brightness and the battery % will still go up.
I also bought a new wall charger recently, which is 850mAh on the USB port and has a 350mAh charger for a loose battery as well, works quite nice.
Has anyone measured the voltage or put a scope on the output of the stock charger?
maybe stock charger has a slight variance in voltage over USB chargers or some signalling going on and this tells the N1 to take more current from it?
I would like a solution to this too I've seen my phone discharge while on a supposedly 1A car charger using co-pilot.
SBS_ said:
I have a 900mAh car charger that I use and it does in fact give 900mAh to the phone while charging. I can tell because I used a 450mAh charger at home before and it was slooow and I could drain my phone while charging it. With the car charger I can stream music with spotify, use the GPS, have the screen on full brightness and the battery % will still go up.
I also bought a new wall charger recently, which is 850mAh on the USB port and has a 350mAh charger for a loose battery as well, works quite nice.
Click to expand...
Click to collapse
Forget the numbers on the chargers - what counts is what really goes into the phone and that needs to be measured with a current meter (test equipment). What you may think to be fast might not be that.
Original HTC chargers obviously do the trick of fast charging but this comes at a price compared to the $3-$4 garden variety on Ebay and the likes.
now I cannot help you with the electronics at all, but, my old HTC Touch Pro charger seems to charge the same as the one which came with the phone, is this correct?
(suits me if it is, as then I have a charger for home and work)
my blackberry bold 2 charger only says it outputs 700MAh, but both the google and htc chargers both say 1.0A
dnts said:
Forget the numbers on the chargers - what counts is what really goes into the phone and that needs to be measured with a current meter (test equipment). What you may think to be fast might not be that.
Original HTC chargers obviously do the trick of fast charging but this comes at a price compared to the $3-$4 garden variety on Ebay and the likes.
Click to expand...
Click to collapse
Yes, it is just anecdotal evidence as I don't have any equipment to measure it. But my phone no longer discharges when I use it while charging, which it used to do with the old charger I used. So while I can say for a fact that the charger I use now is faster, I can't say by how much (this goes for both the car charger and the one I put in the wall socket).
I ordered this charger a few weeks ago and it charges my phone as fast as the original charger. The label says 5v / 1200mA.
Genuine Nokia Mini AC-10U US Type AC Charger (100~240V)
$7,25 and free shipping. (Takes a while before you get it tho.)
GazzaK said:
now I cannot help you with the electronics at all, but, my old HTC Touch Pro charger seems to charge the same as the one which came with the phone, is this correct?
Click to expand...
Click to collapse
HTC Touch Pro = mini USB
Nexus One = micro USB
Not an engineering here, but I am guessing the phone not always drawing more than 500ma may be is to do with the charger itself.
There is this "fast charge" USB standard where a wall plug has the USB data pins shorted to indicate that it is a wall plug and hence the phone knows when to draw more power. So even if the charger is rated 1A, the phone might not know if it could utilize that if those pins aren't shorted. Try doing a quick Google on this ....
If someone can test if the stock charger that came with the phone in fact does have those pins shorted that would confirm part of this theory.
For all practical purpose - I used two cables/plugs with a bench adjustable power supply. Simple micro USB plug would only let me draw 450mA regardless of power supply voltage in the range 4.5-5.5V. Tried shorting data pins - nothing. Tried shorting spare pin to VCC or GND or any of the other pins - nothing.
Used original cable and plug - draws 900mA at voltages from 4.9-5.5.
So it's in the plug somehow.
Tried (very difficult) to see if the pins on the plug are shorted and all 3 spares (except for 5V and GND) seems unconnected.
Next step is the irreversible hot knife...
I'm bugged by this, too. I tested with my desktop dock connected to my car charger (which states 1000 mA): it loads slowly and my battery widget reports USB- instead of AC-charger.
Might it be that the phone tries to load more than 1000 mA at the beginning to be sure that it doesn't overload the charger? And if that fails, it falls back to 500 mA?
Could N1 use a simple logic of:
- always watch the voltage
- start drawing 500ma (or whichever is the lowest current as per USB spec)
- increment in say 50ma steps
- if voltage drops below 4.x V, back off and stay at that level
I just did a little test of my own. I have a Palm Pre car charger (actual Palm brand one labeled as 1000ma output) and I plunged my N1 into it on my way home from work. In twenty eight minutes, my battery went from 47% to 70%. Much faster than plugging into my computer, which is 500ma max. I don't have any fancy test equipment, and don't claim to know a whole lot about electronics, but seems pretty fast to me.
I have a 4-port 2A 5v USB charger, and connecting it to my Nexus OR Milestone with a MicroUSB cable (the one that shipped with either phone, or the one from my Kindle) yields painfully slow charging - it basically won't charge if you are using the phone.
Connecting the Nexus One charger yields fast charging on either phone - so it is not HTC (or Motorola) proprietary.
The Milestone comes with a 900mA USB plug, and connecting THAT to either phone with either of the MicroUSB cables yields fast charging.
I have another aftermarket 2 port 2A 5V USB wall charger (brand: T'nB) AND I have an iPhone USB plug, and both give fast charging on the Milestone, and I have not yet tried them on the Nexus One.
Breakdown (on things I've tried):
FAST CHARGING on Nexus One AND Milestone:
Nexus charger (either in the US (110v/60hz) or in France (220v/50hz) through an adaptor)
Milestone wall French USB plug (which I think is something odd like 850mA at 5.9v) with ANY microUSB cable (in fact, it seems to charge both of the phones faster than the stock Nexus One plug)
SLOW CHARGING on Nexus One AND Milestone:
USB plug on computer
One aftermarket 4 port 2A 5V USB charger (NOT a hub, only a charger)
FAST CHARGING on Milestone, untested with Nexus One
T'nB 2 port 5v 2A USB wall charger
Apple iPhone 1 port 1A 5v USB wall adaptor
Seems found the answer for Fast Charging N1
I had just do some test for Charging N1 With Original AC Charger , Other band USB Charger and PC USB charger.
1. Orginal Charger give N1 from 0% to 100% at about 2 hour and something.
2. The other band AC charger and PC USB Charger can only finish the same job over 5 to 6 hours.
The Fast Charging is Due to 5.1V (Measured at N1) and 5.2V(Measured inside AC charger). 0.1V Drop is due to resistance of USB cable.
The Slow charged is due to 4.8V (measured at N1) and 5.0V (measured on PC USB and Other AC Charger)
i.e. Original Charger mod from 5.0 V to 5.2V (about 10% increase in Voltage)
Looks my theory is correct then ? N1 watches the voltage and if it droops too much, it backs off the current.
So the key would be: get a charger than can maintain at least 1A @ 5.2V, use
a decent gauge, short wire from the brick to N1.
Has anyone tried a Blackberry charger on the N1? Will they work to full capacity as well? (They're on Amazon for a fiver)
Because the nokia charger is working
http://pinoutsguide.com/CellularPhones-Nokia/micro_usb_connector_pinout.shtml
see info under table.
I tested also HP charger + standard USB cable delivered with Nexus, and it is charching cca 1A.
Then I tested one noname Carcharger + standard USB cable delivered with Nexus, and also charging cca 1A.
I dismantle the noname carcharger and here is a result:
data line (pin2+3) is shorted and connected do + (pin1 ,Vcc) thrue resistor cca 630kOhm.
1 - 4 = 5.1V
2,3 - 4 = 3.2V
rashid11 said:
Looks my theory is correct then ? N1 watches the voltage and if it droops too much, it backs off the current.
So the key would be: get a charger than can maintain at least 1A @ 5.2V, use
a decent gauge, short wire from the brick to N1.
Click to expand...
Click to collapse
I try to use power supply 5.2V 2A with cable without dataline (pin 2and3 not connected) and it is charging 480mA only.
I have now tested with an HTC car charger for the HD2. It's fast charging (tested with Waze running, two bluetooth connections and playing mp3 - and it's still loading the battery, whereas before it would be stuck at the current percentage) and even shows AC power instead of USB.
I have older chargers for that output 5.0v / 550mA and have noticed that the Captivate outputs 5.0v / 700mA.
1. Can I safely use the older, 550mA chargers with the Captivate and what will the effect be?
2. Can I safely use the Captivate's 700mA charger with the older phones and what will the effect be?
Thanks.
1. Yes, you can use it. But it will charge slower.
2. Yes, you can use it. I believe that just because the charger output is higher amperage doesn't mean that it will affect the phone adversely. Think of it this way: A lamp is plugged into the wall outlet at your house. That outlet is rated at 120v 15A. The bulb isn't using all 15 amps, so no problem. But if you were to turn the voltage up or down, the lamp will get brighter or dimmer respectively.
The Captivate can take up to a 1A (1000 mA) charger.
Truceda said:
1. Yes, you can use it. But it will charge slower.
2. Yes, you can use it. I believe that just because the charger output is higher amperage doesn't mean that it will affect the phone adversely. Think of it this way: A lamp is plugged into the wall outlet at your house. That outlet is rated at 120v 15A. The bulb isn't using all 15 amps, so no problem. But if you were to turn the voltage up or down, the lamp will get brighter or dimmer respectively.
The Captivate can take up to a 1A (1000 mA) charger.
Click to expand...
Click to collapse
Another question. You sound smart on this so how about using the nexus one car charger on this? Fits perfect and I don't see why not, but still Leary. .. what do you think?
As long as it puts out 5v, (which is USB standard), you are fine. The amperage is only relevant if the device REQUIRES it. For instance if the device draws 1A and your charger could only handle 550mA your device will charge very slowly.
On the other hand if your charger can handle 1.2A and your device only draws 700mA, then your charger will only output 700mA.
The important thing is the voltage, it needs to be 5v +/- 3% ...
I actually use a generic car charger I bought at walmart with 2 USB ports on it, and it works well for every USB powered device I own ... ZUNE, iPOD, phones etc.
OK. Thanks for the reply. I had read that a phone requiring 700mA that uses a 550mA charger could damage the charger and possibly the phone. That's what made me wonder. And that's what led to the question.
Let's make this a bit more interesting. There's a local, highly-reputable cell phone repair store that has stopped selling car chargers because, they say, the rapid charge is not good for the phone's battery. Their recommendation is to use an inverter (no, they don't sell them) so that you can then plug a standard wall charger into it or a USB cable if the inverter is so equipped. The AC current that results from utilizing the inverter is more consistent than the current flowing from a car charger. So...I purchased an inverter for less than $20 and use it to charge the Captivate in my car.
OK ... not sure we need to get this far down in the weeds on this but here goes ....
The USB2 standard for power distribution is 5v and the thresholds are 4.4-5.25V.
Power is supplied in units of 5v power ... 1 unit is 5v at 100mA, no device can draw more than 5 units from any one port. If you have ever seen a portable hard drive with 2 USB connectors it is because it requires more than 500mA to operate and by using 2 ports the device can draw up to 1A. For dedicated chargers the 4.4-5.25v still applies but shorting the D+/- and disabling the data connection allows the device to detect that it is connected to a dedicated charging port and draw a maximum of 1.8A.
In keeping with the above guidelines, when connected to your computer the Captivate can draw no more than 1 unit of power which is [email protected], when connected to a dedicated charger the phone can draw [email protected] and stay within the standard. (yes, it caps itself at 1A, I know).
OK ... the next bit is going to be hard to digest because there are plenty of examples to the contrary ... there is a standard for mobile USB chargers, and it requires wiring them as dedicated charging ports. What this means to us is that, in theory anyway, a mobile USB charger should allow a device to draw up to 1.8A from it (highly unlikely ... but that's the standard as written).
Here is the problem, if the device is plugged into a dedicated charging port and tries to draw it's maximum rated current, that amount of current may not always be available or it may fluctuate. This fluctuation is what causes problems. Have you ever turned you car stereo up real loud and seen your headlights dim in beat with the music? Same thing, the power system is being drawn down. There are a couple of ways to stabalize your power system ... install a large capacitor (mine is 2 Farad) to provide "conditioning", or go the transformer route.A tansformer provides conditioning, but only on its own outputs... while a large cap will condition the entire power system if installed correctly.
So yes, using a quick charger on your phone can cause issues if your car has a ****ty power system or a large stereo system which is not set up properly (again, ****ty power system). Make sure your charging device is within the standard, and you should be fine wether it is USB via a cigarette lighter port or a 110V transformer.
I appreciate your detailed, helpful reply.
Other than the important 5v parameter, what I've taken away from your information is that a car charger can be used in a vehicle with a power supply that is known to be stable, and that either a whole-car conditioning system or an inverter should be used on one with a, shall we say, "less than stable" power supply (PG version ).
Jack45 said:
I appreciate your detailed, helpful reply.
Other than the important 5v parameter, what I've taken away from your information is that a car charger can be used in a vehicle with a power supply that is known to be stable, and that either a whole-car conditioning system or an inverter should be used on one with a, shall we say, "less than stable" power supply (PG version ).
Click to expand...
Click to collapse
Pretty much ...
There's more than one way to skin a cat, and that Transformer will cost you a whole lot less than a 2 Farad capacitor. I hate cats, but they serve a purpose.
@Battlehymn - one more question for you
I have converted from iPhone to the captivate (no haters please) - finally found a physical form factor with specs i like and the captivate rocks.
Anyway, I have some extra external batteries I used with my iphone that i want to use with my Captivate. I just bought a Female iPod connector and I am planning to connect it to a micro USB connector - the pinout is straight forward, but here is my question:
Should I connect the D+/- (short them together)? That is my plan. My batteries are 1900 or 1000 mAH - I assume that even if the phone tries to the draw 1.8A, the batteries have a circuit to only discharge so fast.
I have about 5 Micro USB wall charger laying around, so when I got my Captivate I was happy to see that it used a Micro USB.
My question is.... Is all of the Micro USB power supplies the same? the ones i have are from different Motorola phones.
Thanks,
Coldheat1906 said:
I have about 5 Micro USB wall charger laying around, so when I got my Captivate I was happy to see that it used a Micro USB.
My question is.... Is all of the Micro USB power supplies the same? the ones i have are from different Motorola phones.
Thanks,
Click to expand...
Click to collapse
I assume you mean the wall charger. The charger and the cable are actually separate. You can plug any USB cable into this that has a female USB end. The other end could be mini, micro, ipod, or something else.
They are not all the same - the Moto charger delivers more Amps then the Captivate. Some charger deliver less. The phone will only draw what it is set to, so you can use just about all of them.
cool thanks
The short answer: It's probably fine
The long answer:
USB is a specification, so anything using usb should be designed to run at (for USB 2.0) 4.4-5.25 V. It *should* be fine for charging any microUSB device (the "U" is for "Universal") but I guess it's possible (though unlikely) that the company that made the charger did something funky/proprietary with the voltage/amperage, which would make it not USB even though it uses a USB port. See if the charger says the operating voltage/current on it. It should say around 5V and somewhere in the range of 150-900 mA. If it does, you're golden, if it doesn't say you're still probably fine.
The phone is actually quite picky about chargers. It can recognize a USB charger in either (1) AC wall charger or (2) USB charger. If your paritular charger can be recognized as AC charger, it can be charged in a faster rate if your wall charger can deliver. The Captivate comes with a 700ma wall charger. Some can deliver 1000ma or even higher but Captivate internally limits to 1000ma max from what I read. The higher the amprage, the faster it can charge the battery.
On the other hand, if your charger is recognized as USB charger, not only you will be prompted to select USB mode (if you configured to do so) as if you connect it to a PC, you will also be limited to maximum of 500ma of charging current per USB standard. It will be slower than the stock charger (which is slow already).
foxbat121 said:
The phone is actually quite picky about chargers. It can recognize a USB charger in either (1) AC wall charger or (2) USB charger. If your paritular charger can be recognized as AC charger, it can be charged in a faster rate if your wall charger can deliver. The Captivate comes with a 700ma wall charger. Some can deliver 1000ma or even higher but Captivate internally limits to 1000ma max from what I read. The higher the amprage, the faster it can charge the battery.
On the other hand, if your charger is recognized as USB charger, not only you will be prompted to select USB mode (if you configured to do so) as if you connect it to a PC, you will also be limited to maximum of 500ma of charging current per USB standard. It will be slower than the stock charger (which is slow already).
Click to expand...
Click to collapse
It is not "picky" it follows the USB specifications. For instance I have a 4 port USB wall charger that is capable of supplying 5 volts at 2000 mA to one port or 5v @ 500 mA to 4 ports. Unfortunately the charger is not complex enough to know how many devices are plugged in at once and therefore always signals to all devices to only use a maximum of 500 mA. So if those devices follow the specs they will only draw 500 mA max since it is seen as a high current device (low current devices only should draw 100 mA max).
I DO NOT RECOMMEND ANYONE OPEN UP ANY ELECTRICS EVER ESPECIALLY ONES WHEN CONNECTED TO THE AC LINES IN YOUR HOMES. IT IS A FIRE AND ELECTROCUTION RISK AND I NOR ANYONE ELSE TAKE RESPONSIBILITY FOR YOUR OWN STUPIDITY.
However I hacked it by adding a resistor of proper value between the data pins so that the phone if it wanted to could use the full 2000 mA. Know whenever plugged into that USB port the phone goes into AC mode and from some rough testing during the bulk charging phase the phone charges at a rate of 40% per hour instead of the USB modes 20% per hour. With this hack it takes roughly 3 hours to fully charge since the final charging stage of lithium batteries requires the current to slowly be dialed back. Thats a lot better than the USB modes 5 hours.
icedfire101 said:
It is not "picky" it follows the USB specifications.
Click to expand...
Click to collapse
I say it is picky because without hacking it will only use USB mode for most wall chargers and car chargers out there. It probably won't be any problem for a slow wall charger. But for car charger, 500ma is simply not enough if you also run GPS navigation. The phone uses more than 500ma of juice in that mode. I've to hack my car charger (a 700ma USB charger designed for iPod etc) couple times to let it reliably recognize as AC charger.
foxbat121 said:
I say it is picky because without hacking it will only use USB mode for most wall chargers and car chargers out there. It probably won't be any problem for a slow wall charger. But for car charger, 500ma is simply not enough if you also run GPS navigation. The phone uses more than 500ma of juice in that mode. I've to hack my car charger (a 700ma USB charger designed for iPod etc) couple times to let it reliably recognize as AC charger.
Click to expand...
Click to collapse
Again that is not "picky" it is doing what it is suppose to. What we really need are companies that will follow the USB standards and make Dedicated Charging Ports on there chargers. Most companies cheap out and only make 500 mA and 700 mA products (which that is why charging is so slow). Then they sell it to consumers that don't know any better. Especially with the 700 mA chargers since consumers will think that it is better because of the bigger number but devices that properly follow the USB spec will still only draw 500 mA. (I don't know what specifications Apple follows with their device but since a lot of those that I see with 700 mA are geared toward apples device they may be able to make use of them.) I know of no open specification for a USB device to pull 700 mA.
As to why the Samsung stock charger that came with the phone is 700 mA, I m guessing it is because of cost again. I can tell you though that it doesn't short the data lines with the proper X ohm resister for a Dedicated Charging Port. So I m thinking they made their own proprietary standard there just so they could save a few bucks on each charger but still give the consumer something to feel good about for buying there overpriced stuff.
I DO NOT RECOMMEND ANYONE OPENING UP ANY ELECTRONICS, EVER. ESPECIALLY ONES CONNECTED TO THE AC LINES IN YOUR HOMES. IT IS A FIRE AND ELECTROCUTION RISK AND I NOR ANYONE ELSE TAKE RESPONSIBILITY FOR YOUR OWN STUPIDITY.
Dedicated Charging Ports are required to supply 1800 mA. That means if you try and hack a device that is only rated at 700 mA to be a Dedicated Charging Port the device will possibly overheat and die or cause a fire if any device actually tries to pull the 1800 mA.
As far as car chargers: It is very simple to make a Dedicated Charging Port for a car charger provided you have an old USB one you can mod. Just get a DC-to-DC converter that will convert 11-14 volts (your car battery's voltage range) to 5 volts and throw a X ohm resistor on the USB data pins. Put it all in the empty shell of the donor and your done.
Hi.
I'm looking for an advise about car charger that can charge my TF700.
does anyone confirmed that there any car charger that works?
I mean, I saw some posts that says that ASUS' charger is 15v instead of the more common 5v?
but then I saw the charger, it says " Output : 5v === 2A or 15v === 1.2A"
So I assume I can use other car charger that works with other tablets?
can someone confirm this for me?
THANKS
The tablet will only start to detect a charge at 12V.
Charging at anything lower than that will charge about 1-3% every hour.
ShadowLea said:
The tablet will only start to detect a charge at 12V.
Charging at anything lower than that will charge about 1-3% every hour.
Click to expand...
Click to collapse
oh. okay. any recommendation on what charger should i get?
preferably one with dual USB.
USB is not going to work, in any form or capacity. a USB port can only put out 5V at max.
I use a power inverter that puts out 230V (bought it for my laptop a couple of years ago) through a normal outlet. Plugged the charger into that and it charges normally. You could try looking into that.
ShadowLea said:
USB is not going to work, in any form or capacity. a USB port can only put out 5V at max.
I use a power inverter that puts out 230V (bought it for my laptop a couple of years ago) through a normal outlet. Plugged the charger into that and it charges normally. You could try looking into that.
Click to expand...
Click to collapse
well. if that's the case. I might buy another wall charger...
william tanaya said:
Hi.
I'm looking for an advise about car charger that can charge my TF700.
does anyone confirmed that there any car charger that works?
I mean, I saw some posts that says that ASUS' charger is 15v instead of the more common 5v?
but then I saw the charger, it says " Output : 5v === 2A or 15v === 1.2A"
So I assume I can use other car charger that works with other tablets?
can someone confirm this for me?
THANKS
Click to expand...
Click to collapse
YES the ASUS Transformer will only charge from between 12 & 15V. They DO NOT charge from 5V USB.
I have found that the car chargers which have the ASUS 40 pin plug attached to the cable work fine. They have a regulator circuit which outputs 12V at 1.5A minimum.
The ones available on eBay work well and aren't too expensive. They are a little bulky because of the high current circuitry so look at the pictures and make sure that it looks bigger than the average ones and you will do fine.
unfortunately there's no car charger available as of yet.
Sent from my VS920 4G using xda app-developers app
An Carcharger is avilable, i have one and it is working. 15v 1,2A Carcharger with normal Asus connetor. I'm usin it since 2 Month, never had problems. Carcharger is even cooler as the 230V USB charger while charging. Asus Tabel also switch immediately in charging mode. 14€ at Amazon.de.
By the way, why is everyone saying 5V won't work? On my 230V USB charger there's following note "15V 1,2A or 5V 2A"
Well won't need it, just buy this one ( which i have):
www.Amazon.de/gp/product/B007PQ8AN6/ref=oh_details_o04_s00_i01
Just ignore that tf700t isn't written there and that the charger would have 1,5A. Thats wrong, Carcharger has 15V 1,2A.
If you won't believe me, i can make an picture ( that it will have 15V 1,2A and works) otherwise have fun with it
Speedmastersaxai said:
By the way, why is everyone saying 5V won't work? On my 230V USB charger there's following note "15V 1,2A or 5V 2A"
Click to expand...
Click to collapse
Why aren't you reading everything? I said 5V charges too slowly for the tablet to detect, but it does charge. About 1-3% an hour, which is useless when you're using it. It clearly says, in the manual, that it will only charge over USB (5V) when turned OFF and not connected to the dock. RTFM.
SUH said:
unfortunately there's no car charger available as of yet.
Sent from my VS920 4G using xda app-developers app
Click to expand...
Click to collapse
I don't know how many different threads I have to post this in...
http://www.amazon.com/gp/product/B0081BFYY2/ref=wms_ohs_product
Includes a home charger, car charger, and an extra USB cable, that ALL work. I have been using these with my Transformer Prime, and now my Infinity without an issue at all, and they provide the ASUS required specs for charging and work just like the factory provided chargers.
I ran into this issue with my Verizon Samsung Galaxy Nexus. When attached to a charger, if I went into Settings...Battery... it would show the status of the charging process: it would say "USB" when connected to a computer, and charged at a much slower rate, or "AC" when plugged into the supplied charger in a regular outlet, and charged much more quickly.
With most car chargers, it would only show "USB" but there are some car chargers that have the correct wiring so that it was recognized as "AC" and charged as quickly as when plugged into a regular outlet.
I have two of these in my vehicles, and I just checked one of them, the one listed below first, and with the Tablet plugged into it, it shows as charging, as an "AC" source, just as with my Galaxy Nexus.
Here is the one I specifically tested and verified that it works:
Dual USB Car Charger
I do note the 2 negative reviews there, but all I can say is that I've had this one for almost a year, and it has worked perfectly for me with my phone. A brief test with the Asus Tablet confirmed it was seen as an "AC" charger.
This is the other one I have and which works fine with my phone, although I have not specifically tested it with the Tablet (I have no reason to expect it would behave any differently):
HTC T-Mobile myTouch 3G Car Charger
Obviously, I can't be held responsible if somebody else has a different experience with these, or has problems because of it. Just trying to be helpful and report what has worked for me.
You might consider the i-Blason 12V 2A MINI BULLET STYLE CAR CHARGER FOR ASUS Eee TRANSFORMER from Amazon (Sorry, but noobs can post links)
It's compact, uses your existing cable and delivers 12 VDC @ 2 A. Under $10 US.
Aviator47 said:
You might consider the i-Blason 12V 2A MINI BULLET STYLE CAR CHARGER FOR ASUS Eee TRANSFORMER from Amazon (Sorry, but noobs can post links)
It's compact, uses your existing cable and delivers 12 VDC @ 2 A. Under $10 US.
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Click to collapse
It may work, or it may not. Drawing on my experience with the Galaxy Nexus, there were quite a few car chargers that had specs like this but which in fact were seen as "USB" chargers when used with the Nexus, and I suspect would behave the same way with the TF700T.
I am not an eletrical engineer, but it has something to do with how certain pins are shorted or not, and not all chargers that say they deliver the higher amperage will in fact do so with all devices.
It'll just take somebody to buy and try, and report what does or doesn't work. Per my post above, the chargers that work with my Nexus also work with my Tablet, in being seen as "AC" charging.
DLCPhoto said:
It may work, or it may not. Drawing on my experience with the Galaxy Nexus, there were quite a few car chargers that had specs like this but which in fact were seen as "USB" chargers when used with the Nexus, and I suspect would behave the same way with the TF700T.
I am not an eletrical engineer, but it has something to do with how certain pins are shorted or not, and not all chargers that say they deliver the higher amperage will in fact do so with all devices.
It'll just take somebody to buy and try, and report what does or doesn't work. Per my post above, the chargers that work with my Nexus also work with my Tablet, in being seen as "AC" charging.
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Click to collapse
Don
I have one on order and will pick it up at my daughter's when we go to the US next month. Will post what I learn.
HOWEVER - a true "USB Charger" provides a 5VDC output, not 12- 15 VDC, as does the i-Blason unit I mentioned. Note that i-Blason states very clearly, "Warning: Pls do not use with other MP3 or smartphone... High Voltage could cause burn out."
The difference many smartphones (and other USB ported devices) detect in "USB Chargers" versus "AC Chargers" is max current available (<0.5 A vs >1.0 A) For example, I have a USB battery and a video cam that will both fail to illuminate the charging light if connected to a charging source below about 0.75 A, but still charge, albeit slowly. Both came with 1.5 A USB (5 VDC) wall chargers.
Since the i-Blason is a 12 VDC, not a 5 VDC output, the odds are high it will charge the Transformers at a rate very similar to the wall charger. At least based on electrical "theory". If I had to blind pick a third party car charger, the specs for the i-Blason, to include using the stock cable, were what influenced my choice.
Aviator47 said:
Don
I have one on order and will pick it up at my daughter's when we go to the US next month. Will post what I learn.
HOWEVER - a true "USB Charger" provides a 5VDC output, not 12- 15 VDC, as does the i-Blason unit I mentioned. Note that i-Blason states very clearly, "Warning: Pls do not use with other MP3 or smartphone... High Voltage could cause burn out."
The difference many smartphones (and other USB ported devices) detect in "USB Chargers" versus "AC Chargers" is max current available (<0.5 A vs >1.0 A) For example, I have a USB battery and a video cam that will both fail to illuminate the charging light if connected to a charging source below about 0.75 A, but still charge, albeit slowly. Both came with 1.5 A USB (5 VDC) wall chargers.
Since the i-Blason is a 12 VDC, not a 5 VDC output, the odds are high it will charge the Transformers at a rate very similar to the wall charger. At least based on electrical "theory". If I had to blind pick a third party car charger, the specs for the i-Blason, to include using the stock cable, were what influenced my choice.
Click to expand...
Click to collapse
Appreciate the additional info - will be interested to see if it performs as hoped. I suspect it will, especially based on that warning.
With the advent of the S4, and its higher capacity battery, one could understand a higher charging current. However, I seem to have uncovered some findings that the charging system on the S4 is a bit more complex than first thought!
This is a bit techy, and assumes you have a basic amount of electrical knowledge, ie voltages, currents, resistance etc., but I'll try and keep it as simple as possible for anyone who may not!
To explain: The mains charger supplied with the S4 is a model number ETA-U90UWE, rated 5V @ 2A. However, the phone will ONLY charge at full current (which as I have measured so far, depending on what the phone regulates it to, typically sits in the region of 1.2 - 1.5A), when using the supplied charger (or possibly one of equal or higher current rating, depending on how it's configured internally), AND the supplied usb cable, OR any other usb cable, provided its shielding (the metal outer surface of the connectors) is connected at BOTH ends of the cable. Use a cable that doesn't have this shielding, and the charge current drops, regardless of whether there is plenty of current available or not. Use a different charger with an unshielded cable and the current drops even more, again regardless of whether it can supply plenty more current.
My assumption on this, is possibly an effort by Samsung to avoid the scenario of sticking 1.5 amps down a flimsy cheapo cable, the wires of which will likely be too thin to carry it.
After doing some probing around with a meter, I have managed to find a slight difference with the charger itself, compared to a generic one. In a generic one, the two data pins are usually just shorted together, which tells most phones that it's a mains charger rather than a USB port. On the Samsung one on the other hand, the pins appear to be shorted together, and also connected via resistors across the supply line (known as a potential divider), which holds these shorted data pins at a certain voltage. This is what tells the phone what sort of charger it's connected to.
Attached are a couple of diagrams to show the difference between the two chargers. There are in fact various setups of resistors that different manufacturers use to set the charging current, so it's quite easy to run into compatibility issues!
To make this a little less confusing I have done some preliminary experimenting, and I set out my results here.
For the test, I used combinations of 4 different usb style mains chargers: an apple iPhone one rated at 1A, an iPad one rated 2.4A, an HTC 1A one, and the genuine S4 one. With these I used two cables - the supplied Samsung S4 one (which is shielded), and a cheap generic one (which isn't). I started by measured the charging current directly with a meter, by using a very short usb breakout lead I've made, enabling me to interrupt the 5V line. However, I soon noticed that the use of any extension cables, even shielded, can lessen the chance of maintaining a good shielding connection, so I continued the exercise relying on the "galaxy charging current" app to get a reading.
Charger.................... Cable................ Current (A)
=====================================
HTC 1A.................Generic..................... 0.5
HTC 1A.................Samsung S4..............1.0
Apple 1A...............Generic......................0.5
Apple 1A...............Samsung S4..............1.0
Apple 2.4A............Generic......................0.6
Apple 2.4A............Samsung S4..............1.3
Samsung S4.........Generic...................... 0.8
Samsung S4.........Samsung S4...............1.3
So as you can see from these results, the original charger makes a difference, and the supplied cable (or a good quality shielded one) makes a further difference. If you have any further findings please feel free to add them here.
I can see that this is going to confuse some people, as it has me, as I'm sure some will inevitably try charging up their phone on generic chargers/leads at some point, with potentially long charging times resulting!
.
Very nice findings! Thanks for sharing them.
Not only what you say about longer charging time, but also discharging may occur (it has with me) while connected to the USB. I left my phone with USB tethering and it shut itself down after a couple of hours (it was low on battery already). I wanted to keep all the accessories in "new condition" in case I sell the phone in a few months, but I guess this justifies using the official charger and usb lead.
I hope someone can shed some light on the detection mechanism or the particular characteristics of the official cable so it can be replicated in generic ones.
From your findings, also Appe 2,4A charger has some control on the cable used, thanks.
Yes, but you won't be able to get more than about 0.75A out of it even with the samsung s4 cable.
You could try to add an extension cable to check if the charging system needs exclusively an original samsung cable from the charger to the phone.
Original samsung charger => extension cable male/female => original samsung cable => phone
PS: is there an app to check the charging current?
My experiments used an extension cable, that's the one I made into a breakout cable. So no it doesn't change by adding a cable.
There is an app, called galaxy charging current, which I tried also. In the 0.75A results above it showed a max permissible current of 1000mA, with the fully samsung setup it showed 1900mA. In the lower scenarios is showed up as 460mA. Other than that it doesn't tell you anything, it literally just shows you a max possible current, not the actual current it's drawing.
I've found out what the issue was, my generic cable was obviously a cheap one and wasn't shielded! I have edited my original post to re-explain.
Also I did a further test on a PC usb port - the Samsung cable allowed for 500mA, but the unshielded cheap one only allowed about 350mA, so (as pintycar found out), the phone actually carries on discharging in this case!
Interesting post.
I've been trying to mod a car charger so that the s4 draws more than 300mA so far unsucessful. I'm going to add in the 82K resistance and see what happens.
demusss said:
Interesting post.
I've been trying to mod a car charger so that the s4 draws more than 300mA so far unsucessful. I'm going to add in the 82K resistance and see what happens.
Click to expand...
Click to collapse
Hi,
Using a 5a digital bench power supply, I took a normal micro USB cable, cut it in two, added in the 82k resistors and tested.
Before: 450ma, after 1.73a
Then using a clamp meter I tested it with a 2amp Asus tablet charger - it varied between 1.48 and 1.61 amp.
I have since built a few more cables - one to use in my car (again 2 amp charger).
All in all, it works very effectively. Thanks for the initial research (saved me having to open my charger.)
BTW I suspect it is the charger where the resistors are, not the cable, otherwise the phone would try to pull 1.5a + from a laptop if you connected it.
Left my samsung cable at work so will test it tomorrow (if I remember)!
W.
Interesting. So basically for us laymen, you are telling us to use the original charger and cables to the extent possible ... right?
Can you clarify to me what an unshielded cable is? Maybe with a picture? I've got a blackberry's cable at work connected to my PC.
At home, I also have a cable and charger that I got with my Nexus S (I think this says Output 5.0V ~ 0.7A).
Would this be a problem or can I get by with these?
Thanks
I've been using the Samsung cable+charger+USB extension cable and charging the S4 usually takes about 4 hours, I'm going to try with just the Samsung cable next time and see if it makes any difference since people are saying that theirs can be fully charged within less than 3 hours.
Paparasee said:
Interesting. So basically for us laymen, you are telling us to use the original charger and cables to the extent possible ... right?
Can you clarify to me what an unshielded cable is? Maybe with a picture? I've got a blackberry's cable at work connected to my PC.
At home, I also have a cable and charger that I got with my Nexus S (I think this says Output 5.0V ~ 0.7A).
Would this be a problem or can I get by with these?
Thanks
Click to expand...
Click to collapse
Hi,
I believe (guess work here ) that only the original charger "needs" a shielded cable - could be checked by shorting the ground and shield on one side and see if it works at the higher current - if I am bored I may do it - it probably checks the shield and limits the current if it is not there (note I have not tested this so only going by the first posters findings).
BTW a shielded cable has a wire mesh around the 4 internal cables - this mesh avoids external interference messing with the signals. Can't see it affecting the charging though BUT shielded cables tend to have thicker internal cables so could be related to this.
I have it charging at 1.7a on an unshielded cable (thought he power strands are thicker than average) Shielding should only affect the data transfer speed, not the charging current.
If the Nexus S has only a 700mah charger then this will not be able to provide enough current for high speed charging and could easily burn out - nice smell, dead charger, not much else. therefore only use a normal unmodified usb cable (and it will charge at about 450mah).
W.
all this would eexplian why the charger that camewith my S2 dosen't appear to charge my phone fully over night...
For what it's worth I'm charging with a Note 1 charger...a thick shielded cable via the S3 docking station....and getting 900mah...
will get my original cable tonight and have a go tomorrow...
interesting read, my s4 lead and charger are still in the box and I'm using my nexus 10 ones phone charged from about 30% to full in just over 2. may have to change the old HTC £2 lead I've got connected to my works pc then, maybe why it's struggling to charge when playing music. guess this is one way to get people to buy more expensive cables
Very interesting read, thanks TS.
My original charger and cable set is still in the box; I've been using my Mom's old Galaxy Note charger.
I'll try the original cable + wall mount and see how fast it is compared to my current charger.
wmccann2 said:
Using a 5a digital bench power supply, I took a normal micro USB cable, cut it in two, added in the 82k resistors and tested.
Click to expand...
Click to collapse
Can you show me your final cable with a pic? Thanks
After this thread I have stopped using my blackberry bold cable to charge s4 and of course the cheap one too.. thanks op!
Sent from my GT-I9500 using xda app-developers app
I'm not sure if shielded vs. unshielded is the difference - probably wire gauge is the difference.
For example, if you shop at Monoprice, you have two options for USB cables: 28 gauge cables, and 24/28 gauge cables.
For wire gauge, lower is larger - the 24/28 gauge cables have thicker wires for the + and GND lines. A pure 28 gauge cable is likely to drop voltage a bit at high currents, and my observations have been that most newer devices, ESPECIALLY Qualcomm-based ones, are VERY finicky when it comes to input voltage drops.
As to the charger itself:
Apple chargers are almost guaranteed not to charge at full current, as they don't conform at all to the USB battery charging standard. Some newer Android devices do have at least partial detection of Apple chargers, so they may charge at 1A if an Apple charger is detected (any Apple charge, even 2.1A ones).
It sounds like the included official charger is a tablet-compatible one. Samsung tablets expect D+ and D- to be held by the charger at 1.2 or 1.8 volts (I forget which). As a result, Samsung tablets will not charge from standard chargers (like an N7 charger), but standard devices (like an N7) will charge from Samsung tablet chargers.
Now, the question is: Does the GS4 *require* a Samsung tablet-style charger, or did Samsung just include a tablet-style charger because it's backwards-compatible with standard devices? (less part numbers to track in inventory).
A useful pair of points would be: Using the same cable, does the Samsung charger behave significantly different from a Nexus 7 charger?
wmccann2 said:
Hi,
Using a 5a digital bench power supply, I took a normal micro USB cable, cut it in two, added in the 82k resistors and tested.
Before: 450ma, after 1.73a
Then using a clamp meter I tested it with a 2amp Asus tablet charger - it varied between 1.48 and 1.61 amp.
I have since built a few more cables - one to use in my car (again 2 amp charger).
All in all, it works very effectively. Thanks for the initial research (saved me having to open my charger.)
BTW I suspect it is the charger where the resistors are, not the cable, otherwise the phone would try to pull 1.5a + from a laptop if you connected it.
Left my samsung cable at work so will test it tomorrow (if I remember)!
W.
Click to expand...
Click to collapse
I missed this post on my first read-through: What happens if you just short D+ and D- when using the bench supply?