Hi,
I bought a wall charger for my N1 today. I was searching for one with 1000 mA output so the phone would charge twice as fast, but after having it on for a long time and seeing that it was only 22% charged, I looked at the battery status and it said "USB". I unplugged it, plugged the stock adapter and it said "AC", and started to charge at the usual speed.
Is there a way to have wall chargers that are NOT the ones provided by HTC charge at a normal speed? thanks!
Interesting... it happens the same thing with an iPhone charger, which have the same output characteristics as the stock charger. I never thought looking at the battery status
FWIW, you can easily see if your phone is charging fast or slow by installing the quick system info app (AC=fast, USB=slow).
I'm using the 1000 mA charger with the USB to micro USB cable that came bundled with the phone. Might it be the cable limiting the power?
I've been trying to figure this out too...
I bought a USB car charger to charge my phone in the car whilst driving.
However even with my phone on standby it still loses power.... I don't know whether it's because I'm using the USB cable or the charger is inferior.
It is rated a 1000mA (the charger).
I bought the HTC car charger from expansys.. bit costly at around £20 for a charger but it works perfectly for me. Drove 4 hours with copilot running, and battery remained perfectly charged
As well as the stock charger, I often use a pikie USB charger with a Nokia micro USB cable... phone reports an AC charger in use.
I've read that the Nexus 7 charges via regular micro USB (no proprietary port or cable) and that the charger is a 2A charger. Has anyone figured out the proprietary aspects of the charger that signal to the Nexus 7 that it's connected to the charger and that it's ok to draw 2A?
Bump.
I think it just dumps 2A into all the devices. 99% of USB devices have resistors in them to limit the current
Sent from my Nexus 7 using xda app-developers app
It needs a 2amp charger... 1amp will keep it on indefinitely but wont charge... with less than 1amp (say keyboard USB port) the battery will lowly drain on while the power indicator shows charging and eventually the screen will go nuts and the device will crash/shutoff
Sent from my Nexus 7 using xda premium
pixelchemist said:
It needs a 2amp charger... 1amp will keep it on indefinitely but wont charge... with less than 1amp (say keyboard USB port) the battery will lowly drain on while the power indicator shows charging and eventually the screen will go nuts and the device will crash/shutoff
Sent from my Nexus 7 using xda premium
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Don't think you are accurate. If computer usb can charge the device (0.5A from usb port on computer), any charger can charge n7, albeit charger with lower current will take longer to fully charge the device. Tried 1A charger on N7, no problem.
Sent from my Galaxy Nexus using xda premium
There is the standard CYA in the manual to only use the cable and charger supplied with the unit. If it is fully powered down, pretty much any microUSB will charge it... eventually. That's not necessarily the best thing for the battery. If the power is under 2A as suggested, depending upon what you're doing with the tablet, it may just be enough to keep it running, or, could actually drop to zero even in use. (This happened with my Nook Color, for example). YMMV, but on the stock charger, the recharge is pretty quick. My only quibble is that there is no notification light to alert you to charge completion, or other notifications you might get (gMail, texts through Google voice, etc.).
tylerwatt12 said:
I think it just dumps 2A into all the devices. 99% of USB devices have resistors in them to limit the current
Sent from my Nexus 7 using xda app-developers app
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This is incorrect. It's not up to the charger to push 2A, but rather up to the device to pull 2A through signaling of specific voltages on the data lines. For example, if you were to normally plug any tablet besides an iPad into an iPad charger (2.1A), the most you can expect to pull is 1A because the tablet doesn't know that it's connected to a 2.1A charger. The internals of the iPad charger will only tell an iPad that it's connected to a 2.1A charger. In order to charge at 2A with another tablet on the iPad charger, you need to do something like this example with the Galaxy Tab:
http://forum.xda-developers.com/showthread.php?t=845844
Or buy a pre-made adapter:
http://www.dealextreme.com/p/usb-ma...ung-galaxy-tab-p7500-more-black-127843?item=6
So the Nexus 7 charger must have something going on to tell the Nexus 7 that it's connected to the right charger because it can't try to pull 2A from every USB port that it's plugged into (some computers will actually shut down if something tries to draw too much power through the USB ports).
bitbearmi said:
My only quibble is that there is no notification light to alert you to charge completion, or other notifications you might get (gMail, texts through Google voice, etc.).
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Click to collapse
NoLED can alert you about notifications by flashing icons corresponding to the notification on the screen. It turns the screen on, which will obviously drain your battery, but there's a setting to disable turning on the screen when the proximity sensor is "close", so what you can do is put it screen-side down when it's off the charger to keep it from turning on the screen. It's not as elegant as a notification LED or backlight notifications (which is what I'm used to), but it's better than nothing.
Something I'd like to add not sure if its true but it was an explanation relating to this I saw when shopping around for an in car charger and makes some sense.
Android will reduce the power it pulls from a USB port if it detects it as a data port as opposed to an AC connection in order to conform to the official USB specs.
Apparently some chargers are wired incorrectly (data pins should be cross connected in chargers for it to be recognised as a charger if I remember the description) and will be picked up as a data port. Some devices will just use as much power as possible on data ports but ones that conform to the specs will take only the amperage outlined in USB specs.
Like I said its just something I remember don;t shout at me if I'm talking mince.
Sent from my Transformer while the N7 is lost in the Play Store Black Hole.
16gb N7 UK ordered 3rd July.
It's mildly related to proper charging. Basically, for any tablet, there are three charging states. The first is USB mode, where the data pins aren't shorted (as if the device was connected to a computer's USB port), which draws a maximum of 0.5A. The second is AC mode, where the data pins are shorted, which draws a maximum of 1A. The third mode is what I'll call high speed AC, and this is the mode we're after. Not only are the data pins shorted, but voltage is being applied to the data pins in a specific way to each device family. When the device detects this mode, it'll think that it's connected to its own charger and try to draw up to 2A.
Every device family has its own required voltages on the data lines, and by families, I mean products that have interchangeable chargers (like iPads, Galaxy Tabs, Transformers, etc) so if we can figure out what the Nexus 7 needs, then we can use any 2A charger with it (like using an iPad car charger). I just realized that others have said that they were able to charge at high speed with their Transformer charger, so I suspect that we can refer to Transformer charging adapters to get it working.
I haven't taken apart my Nexus 7 charger to see what's inside mainly because I've only got the one...
but I did verify that the D+ and D- pins on the USB are shorted, but there is no discernable voltage being applied to either.
So I set up my meter (and sacrificed my really short asus OEM charging cable) to measure the current draw while charging... this is what I found:
OEM charging cable appears to be just a regular old USB cable, unless there is something happening in the micro usb end, which I really doubt.. but I don't have any adapter to check if this is the case.
When D- and D+ are floating and not shorted together, the Nexus 7 draws ~1A but the charging indicator does not come on.
When D- and D+ are shorted together the Nexus 7 draws ~1A and the charging indicator does come on.
I could not get the Nexus 7 to draw 2A. Maybe I broke something
-J
Thanks for making the sacrifice. I guess more testing is needed.
I think the theory that it doesn't draw more than 1.0a may be correct. But it is still finicky about the charger. I have a palm OEM charger with palm cable and it doesn't charge the N7. I have a Nokia 1.2a charger and Blackberry 1.8a charger and they both seem to charge near the same rate, as fast as the Asus OEM charger.
Just as another data point, I tried connecting my n7 to the ipad ac charger, which is a 2A charger. It doesn't charge at all against the ipad charger.
kmandel said:
Just as another data point, I tried connecting my n7 to the ipad ac charger, which is a 2A charger. It doesn't charge at all against the ipad charger.
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Anybody with the N7 that charges on the iPad charger? If so, I want to return it.
Domi
Limited charging options
dmalovic said:
Anybody with the N7 that charges on the iPad charger? If so, I want to return it.
Domi
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It won't charge off an OEM iPad charger, just checked. It also won't charge off a Monoprice 3x outlet with 2x 2.1a usb directly connected to the usb ports or a 2.1a backup battery. Damn device is really picky about the source.
It will charge off my Touchpad and Vizio tablet charger.
I'm really bummed out it won't charge off the monoprice 3x outlets 2x usb since I bought a bunch of them when they were on sale and put them through out my house.
kkeo said:
It won't charge off an OEM iPad charger, just checked. It also won't charge off a Monoprice 3x outlet with 2x 2.1a usb directly connected to the usb ports or a 2.1a backup battery. Damn device is really picky about the source.
It will charge off my Touchpad and Vizio tablet charger.
I'm really bummed out it won't charge off the monoprice 3x outlets 2x usb since I bought a bunch of them when they were on sale and put them through out my house.
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Same here.. just tried an ipad charger and it didn't work.. this is the oem ipad 3 charger. Also tried ipad 1 charger (should be same thing) didn't work.. going to try a charger for a Dell Streak 7.. see if it works.
Mine is also very picky. I used the stock Asus charger with a longer micro usb cable and it didn't charge while I was using the tablet over a period of around an hour. It maintained the % charge of the battery but didn't increase it. When I went back to the stock cable, it charged during use. Wouldn't be a real big deal if they hadn't scrimped on the cable to where it's only 3 feet long. What a pain.
A little OT, but my ASUS 1366 motherboard has an update you can install that allows the USB ports to charge an iPad at 1 amp instead of the normal .5 amp. I haven't tried it with the N7, but I suspect it won't work. Maybe another update will be released considering they make both devices, although my mb is kind of old...2009. I wonder if the USB2 specs allow for 2A charging and also if the newer USB3 spec allows more amps to be provided. If it doesn't, it should considering some of the latest power hungry devices.
Sent from my Nexus 7 using xda app-developers app
I looked at this too, and tried a few different configurations.
Measurements taken with my N7 at 95% charge. I expect higher power draw at lower charge.
.445mA - PC USB port
.440mA - APC USB battery pack directly connected
.443mA - iPhone 3G USB charger
.820mA - stock charger
.815mA - APC USB battery pack with D+/- disconnected at the host and shorted at the device end (actually 10 ohm resistor)
.818mA - APC USB battery pack with D+/- removed on host, shorted on device, and resistor divider for 1.2V on both pins (Samsung type)
I chose the APC battery pack as it provides a solid 5V at 1A. It also has D+/- wired iPhone-style.
Wondering what the charger driver thinks of this, I looked at dmesg just after every attempt. I see:
connected to PC USB:
Code:
smb347_charger: [cable_type_detect] Reg3F : 0xc0
smb347_charger: [cable_type_detect] Reg3E : 0x0c
Cable: SDP
========================================================
battery_callback usb_cable_state = 0
========================================================
connected to iPhone or APC charger:
Code:
smb347_charger: [cable_type_detect] Reg3F : 0xc0
smb347_charger: [cable_type_detect] Reg3E : 0x0b
Cable: OTHER
========================================================
battery_callback usb_cable_state = 0
========================================================
connected to stock, or APC with either of my adapters (cut & shorted or Samsung):
Code:
smb347_charger: [cable_type_detect] Reg3F : 0x83
smb347_charger: [cable_type_detect] Reg3E : 0x0a
Cable: DCP
========================================================
battery_callback usb_cable_state = 3
========================================================
So the charger limits to ~500mA when using an iPhone-pinned charger (OTHER) or a live USB host (SDP), and allows high current charging when D+/- is shorted regardless of being pulled to a given voltage. SDP is USB 2.0. charging spec terminology for Stanard Device Port, meaning a 500mA limited USB port, while DCP means Dedicated Charging Port which means that D+/- are shorted and can supply up to 1.5A.
This uses the SMB347 USB charge controller, same as the Kindle Fire, which works the exact same way.
TL;DR: Cut D+/- between the charger and device and short D+/- at the device for full current charging.
At home I have an iPhone 5 charger and a Blackberry Bold 9900 Charger along with a Cooler Master Battery Bank. The out put on the battery bank claimed 5 Volts 2.1 Amps but when hooked up to my HTC One it showed USB Charging. I hooked it up via my iPhone 5 charger which has an output of 5 Volts and 1A and also got USB Charging but when I hooked it up via Blackberry Charger with an output of 5V / 750 mA I got Charging (AC) on my HTC One. Looks like it won't accept any higher power input than what it needs for faster charging.
Picture posted is via Blackberry Charger.
Here is a picture via Cooler Master Battery Bank showing charging (USB)
The maximum current is drawn when the battery is empty. The first phase of charging is constant current, where it will draw up to 1A from AC and 500ma from USB, then moves to constant voltage, where the current will drop off. Your battery is probably too charged to be drawing max current.
HTC phones switch to AC charging when the data pins on the USB are shorted, otherwise it's USB charging.
BenPope said:
The maximum current is drawn when the battery is empty. The first phase of charging is constant current, where it will draw up to 1A from AC and 500ma from USB, then moves to constant voltage, where the current will drop off. Your battery is probably too charged to be drawing max current.
HTC phones switch to AC charging when the data pins on the USB are shorted, otherwise it's USB charging.
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I need to double check which USB cable I had used. At work now but just saw that the USB cable I had at work was the Blackberry USB Cable and when I hooked that one up with my new HTC ONE I got AC Charging on my HTC ONE. A sales person had told me that the USB cable can make a difference at times. Will try messin around with a few wires along with my Cooler Master Battery Bank to see if the results change.
desiregeek said:
I need to double check which USB cable I had used. At work now but just saw that the USB cable I had at work was the Blackberry USB Cable and when I hooked that one up with my new HTC ONE I got AC Charging on my HTC ONE. A sales person had told me that the USB cable can make a difference at times. Will try messin around with a few wires along with my Cooler Master Battery Bank to see if the results change.
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I find that the charger it came with charges it fastest. The other chargers I have used are my neuxs 4 and gs4.
The phone is looking for a 'short' across the two data wires, I believe. The HTC chargers have this so that the phone knows it's not a USB port that isn't able to deliver the current. I'm surprised the blackberry charger fooled the phone to think it's AC.
So its been a while since my s4 i9500 wall charger's cable been cut. Although the phone does get charged up. It isnt charging up quickly as it used to before the wire was cut. Sometimes the phone doesnt even charge even thought the battery icon shows that it is charging.
Now, I have been thinking of replacing the charger. But do i have to buy the charger or should i just replace the cables? I have a lot of micro usb cables . Can i use them with the adapter to charge up my phone?
You can use quite literally any micro-usb 2.0 cable and any usb charger to charge it; however, to achieve the maxium charging speed (1900mah) you will need a high quality shielded micro-usb cable (like the stock Samsung cable) and a 2A (or higher) usb charger (like the stock Samsung charger or an iPad charger).
I have both a QC car charger and a USB C to USB C charger as well.
I know USB C gives 5v/3A and QC gives variable charging from 9v/1.67A and down (QC 2.0)
Anyone run tests?
the phone lockscreen gives you an estimate on how fast your phone will charge to 100% when it is plugged or on a wireless charger. Less time, faster charger.
If I use my S7 cable with the USB-C adapter, it charges 3 times faster than the adaptive wall charger.