Has anyone successfully used a 12v usb charger other than the BN ripoff? I have a gmax 2.1a and aluratek 2a and neither one will charge the bn tablet. I get the "not charging" message on the tablet.. so I supposed its getting some juice, but not enough to sustain it. I soldered d+/d- together on both adapters and now both will show ac charging in the nexus - so I know each is getting close to 1amp. Ironically, the tablet will show ac charging if I use the nexus power ac power cube which is rated at 5v / 1amp output. So you would think the 12v usb adapters which are rated the same would work as well.
thoughts?
darby427 said:
Has anyone successfully used a 12v usb charger other than the BN ripoff? I have a gmax 2.1a and aluratek 2a and neither one will charge the bn tablet. I get the "not charging" message on the tablet.. so I supposed its getting some juice, but not enough to sustain it. I soldered d+/d- together on both adapters and now both will show ac charging in the nexus - so I know each is getting close to 1amp. Ironically, the tablet will show ac charging if I use the nexus power ac power cube which is rated at 5v / 1amp output. So you would think the 12v usb adapters which are rated the same would work as well.
thoughts?
Click to expand...
Click to collapse
did you read about the 'special' connector that is deeper than the normal ones ? please use the search function for more info.
sure did.. all of this was with the [email protected] cable..
old_fart said:
did you read about the 'special' connector that is deeper than the normal ones ? please use the search function for more info.
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Click to collapse
There's also the part of the equation where the USB adapter must supply a lot more than the 500mA of current that most adapters and computer USB ports are limited to. Mine will say "charging" as long as the adapter puts out around 1A (1000mA) or more and I use the NT's supplied cable. <-- But it still won't charge as quickly as it does when I use a 2A charger such as the one it came with. The factory charger is around 2A and expecting the NT to charge with anything less may not result how you'd like. Just because your phone likes a charger doesn't mean your NT will.
There is more to it than just shorting the D+ and D- pins. If the charger was designed for iPad, then you will also need to remove 4 resistors. Check out the two links in my post relating this issue at http://forum.xda-developers.com/showthread.php?t=1614091
I modded a car charger by just shorting the two pins. My HTC EVO 4G phone showed AC charging but my NT showed USB charging. I opened it up again and removed the resistors network and NT showed AC charging right away. Good luck.
bigdogz - good advice - made an attempt at it but my eyesight and hand steadiness aint what it used to be However, I did find one that works - Scosche reviveII - GUSBC3. Its a 2.1a port for the galaxy tab and a 1amp port for apple. It charges both the galaxy tab 10.1 and the nook tablet on the 2.1a port. It also will charge in ac mode a galaxy nexus from the tab port. The 1a port does not have the d pins shorted, but will charge an iphone.
Related
http://maxborgesagency.com/press/bracketron-launches-dual-usb-charger/
$24.99 dual USB Cigarette lighter adapter 1 & 2 amp
Reeves360 said:
http://maxborgesagency.com/press/bracketron-launches-dual-usb-charger/
$24.99 dual USB Cigarette lighter adapter 1 & 2 amp
Click to expand...
Click to collapse
Unfortunately, worthless.
Transformer needs 11v-15v to charge reasonably well. Any 5v charger, even at 1000000 amps, will not charge the TF with screen lit, or charge takes days with TF turned off.
Much harder to find auto chargers in the 11v-15v range, some that say 12v are actually not. I found one advertised as 12v (that measures 9.8v actually) and it also did not charge TF. Good luck.
Wont work. Unlike most devices the Transformer does not use 5v to charge like the iPhone and many other Android devices. It does use USB but it will only charge via Asus's special chargers. This is because our Transformers charge via 15volt and the charger cable is actually a USB 3.0 cable that has extra pins in back, and the 15volt pin is one of these extra pins the USB 3.0 layout provides.
Edit Bob Smith42 beat me to it by a few seconds lol
Be aware that it's incorrect to say that the TF won't charge from a standard USB charger. It does charge however it only trickle charges and therefore takes much longer. So let's make sure we are clear when we respond about what works and what doesn't. I used my iPad 2 amp charger on the TF and went from about 30% charge to about 85% charge in about 6 hours (screen off). The absolute fastest way to trickle charge from a generic adapter is with the TF powered off. Hopefully Asus will come out their own car adapter for the TF.
The charger that the original poster mentioned WILL trickle charge the TF. Also new TF users should know that the TF will not give any charging indications when plugged into anything other than the Asus charger - but it is trickle charging none-the-less.
w4rmk said:
The charger that the original poster mentioned WILL trickle charge the TF. Also new TF users should know that the TF will not give any charging indications when plugged into anything other than the Asus charger - but it is trickle charging none-the-less.
Click to expand...
Click to collapse
One thing to mention that you can do if you have the tock is trickl-echarge THAT while still using the pad... then in 5-6 hours when the padd is getting low, you can dock it, and it will charge off of the dock while you keep using it. Once fully charged, undock it again, etc. This is what I want to do, and why I want a second USB cable.
Anybody tried to use standart HTC 5V wall charger for Flyer?
I have HD2 and its charger can safely give 1A. This type of chargers have USB data pins shortened. So all HTC devices conneced by standart USB cable identifies it as AC charger. I have tried to connect Flyer for a half a minute. Charger was identified as AC and as I remeber (not shure...and afraid to test once more) Flyer was sucking more than 1A (Battery monitor pro).
Flyer AC charger is 9V 1.62A, standart charger 5V 1A so question is do Flyer detects difference between Flyer charger and Standart 5V charger? Is it safe and possible to use standart 5V charger?
yes you can use standard USB, it will just charge slower
DigitalMD said:
yes you can use standard USB, it will just charge slower
Click to expand...
Click to collapse
Have you tried or you just think so?
If flyer tries to get more than 1A, yes it will charge slower, but it will also burn charger.
I charge with reg usb all the time
Sent from my PG86100 using XDA App
I do it routinely. The device cannot draw more than the usb port will supply. PC ports supply only 0.5 amp. So they will only work if you turn the power off the Flyer. Wall chargers vary, some supply 1 amp. The original is 9v 1.6 amp were usb chargers typically are 5v so they will charge slower, much slower in some cases.
DigitalMD said:
I do it routinely. The device cannot draw more than the usb port will supply. PC ports supply only 0.5 amp. So they will only work if you turn the power off the Flyer. Wall chargers vary, some supply 1 amp. The original is 9v 1.6 amp were usb chargers typically are 5v so they will charge slower, much slower in some cases.
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Click to collapse
Sorry for last several anoying questions. Just want to be shure.
1. Do you use HTC charger or other vendor? In most cases only HTC 5V chargers are identified as 1A AC chargers. If not - device will not request more tha 500ma in order not to burn USB port (device thinks that it is port in that case)
2. Did you see that Flyer identified charger as AC source?
3. Did you charge when battery was less than 10%, what was charge current value on Flyer
Ok, now its getting annoying, did you actually read the information I put in the post you quoted? You just ask me the same questions I already answered.
The chargers all run on AC and produce DC . Flyer original output is 9 Vdc 1.6 amp .
DigitalMD said:
Ok, now its getting annoying, did you actually read the information I put in the post you quoted? You just ask me the same questions I already answered.
The chargers all run on AC and produce DC . Flyer original output is 9 Vdc 1.6 amp .
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Sorry but I think you did not gave the anwer. My english is not so good so maybe the question was not clear. I will try to explain once more, it is up to you to answer or just end this conversation/thread if you think i asked same stupid question once more.
1. Usually non HTC 5V chargers on HTC devices are identified as USB port and thats why devices draws no more than 500mA. It made so no to burn USB port.
2. All 5V HTC chargers on HTC devices are identified as AC 1A, so devices try to get as much as thay can (usually phones request less than 1A).
3. HTC Flyer with empty battery can request no more than 9*1.6A=14.4W. Flyer charger can handle that. Standart can handle only 5*1A=5W.
The question was: do 5V 1A HTC charger will not burn because Flyer identifies charger as AC and can request more than 1A. USB ports usually have protection from current. I do not know if 5V HTC chargers has protection or do Flyer identifies difference between 9v and 5v chargers and sets max current it can get from charger?
extra pins not present on a usb cable for mains charging. if using usb cables the the flyer is a usb device and has the same power restrictions as any other device...simple as that.
globatron said:
extra pins not present on a usb cable for mains charging. if using usb cables the the flyer is a usb device and has the same power restrictions as any other device...simple as that.
Click to expand...
Click to collapse
You are not right.
HTC 5V HTC mains charger comes with standart USB cable with no extra pins. Thats true. But mains charger has Data+and Data- shortened inside what makes HTC phones think that it is mains... with any USB cable. So power restrictions will not be as for USB....but as for AC. I have tested that in practice. I made belkin car charger and iphone charger able to be treated as mains chargers just by connecting pins (iphone charger data pins should be disconnected from schema before connecting. I have secret how to connect pins without opening unopenable iPhone charger....).
So the question is Flyer is able to identify mains 5V1A and 9V1.6A difference and do it apply different restrictions. Now for both shows it as AC source and I think sucks as much amps as it can up to 1.6A. So teoretically it should burn 5V charger if it will suck more than 1A.
What are you trying to do exactly?
---------- Post added at 06:29 PM ---------- Previous post was at 06:28 PM ----------
by the way, it is standard, not standart.
I use the Flyer with a variety of USB wall chargers, car chargers and PC ports and have never experienced fire or explosion, only charging and slow charging. Are you trying to figure out how to use a different charger and still get a rapid charge rate?
Ok, I think I understand what the question really is but it is poorly phrased.
On my previous statement I agree with your answer in terms of how it is possible to read what I had said, in fact probably the logical way to read it on re-reading what I wrote, what I meant was electrically present, not that there were extra physical pins, whether electrically present is hi or lo doesn't matter.
If the question is can you rapid charge at 5V from a sufficiently powerful 5v then the answer is no, even if you pull D+ and D- to ground. Also it is highly likely that in the AC charger a resistor rather than direct connection is used to pull them to ground and these resistors could be electrically significant in the overall charging circuit.
The most probable reason for this is that there are two parallel charging circuits in the flyer ( almost certain of this ), and hence why 9v is used. The charge voltage for a 3.7v battery is 4.2 volts and somewhere around 500-750mA, the second charging circuit will have an isolation circuit to ensure that it is only engaged for charging purposes and does not directly feed the tablet that would be the purpose of the modified connections of d+ and d-, activate the secondary charging circuit.
Assuming you feed the device 5v from usb that would mean that the second circuit would receive a 0.8v supply, probably (hopefully) not enough to activate it so you just burn up the extra as heat in the circuit. In theory you would see a higher current draw by asking the flyer to run as if it was connected to an 9v supply when you connect a 5v supply. Best and most likely case scenario you're just being inefficient, medium case you burn out a component or protection (eg thermal fuse), worst case scenario you reverse the battery and it gets damaged or explodes.
globatron said:
Assuming you feed the device 5v from usb that would mean that the second circuit would receive a 0.8v supply, probably (hopefully) not enough to activate it so you just burn up the extra as heat in the circuit. In theory you would see a higher current draw by asking the flyer to run as if it was connected to an 9v supply when you connect a 5v supply. Best and most likely case scenario you're just being inefficient, medium case you burn out a component or protection (eg thermal fuse), worst case scenario you reverse the battery and it gets damaged or explodes.
Click to expand...
Click to collapse
This is what i meant! I was curious which one of scenarious will happen in practice.
From DigitalMD post above I can make a conclusion that in reality we will have 1st scenario (just inefficient).
Thank you guys.
I recommend you look at the following USB battery charging spec. A properly designed charging circuit will have current limiting and can recognize the power capabilities of the port vs. device vs. cable. This is why some charging circuits use a special cable vs. a standard USB data cable.
http://www.usb.org/developers/devclass_docs/Battery_Charging_V1_2.zip
Nice link, it's got some pretty decent information in it.
Honestly to answer your previous question I can't tell, I'm guessing nothing except some heat, but that doesn't mean that you couldn't thermally damage something ( eg the screen ).
globatron said:
Nice link, it's got some pretty decent information in it.
Honestly to answer your previous question I can't tell, I'm guessing nothing except some heat, but that doesn't mean that you couldn't thermally damage something ( eg the screen ).
Click to expand...
Click to collapse
I think that there is no chance to damage Flyer thermally But theoretically, if Flyer wll requests more than 1A charger can overheet and possibly damage the Flyer. But if Flyer can detect that charger as 5V1A and if it can request less than 1A, then it is safe. Also if charger can detect current higher than 1A and can limit it - that also should be safe to use it.
I will read pdf maybe there will be some good info.
I use a self powered usb hub as a daily charger for both my Flyer and Kindle. Works fine. With no "burning out". At work, I use a generic 5v 1a charger, no problems either except for charge speed...
The charge state shows USB instead of AC, so it appears there is some sort of voltage/amp sensing going on?
Sent from my Nexus One using Tapatalk
kardain said:
I use a self powered usb hub as a daily charger for both my Flyer and Kindle. Works fine. With no "burning out". At work, I use a generic 5v 1a charger, no problems either except for charge speed...
The charge state shows USB instead of AC, so it appears there is some sort of voltage/amp sensing going on?
Sent from my Nexus One using Tapatalk
Click to expand...
Click to collapse
Your flyer identifies charger and hub as USB and limits current to 500ma. The initial discussion was about the case when 5V1A charger is identified as AC. This case happens when standart htc phone charger is used (eg HD2 charger). That charger has data pins shortened inside that makes HTC phones (conected by standart USB cable) think that charger is AC. Surprisingly Flyer identifies it also as AC. In that case flyer do not limit current and possibly tries to draw 15W from 5V charger which can deliver only 5W ! I think that good chargers should have protection from oveload....
So soldering data pins together in you generic charger would make it more efficient. I modified my all generic chargers even genuine iphone charger and now all HTC and possibly other phones identify them as AC !! But I still not shure is that safe for flyer.
Little bit offtopic:
Yesterday i dissasembled Griffin car charger thas has 2x1A USB ports. In fact there is a chip inside that can deliver up to 3A. The chip is XL1583E1. This chip can be set to deliver other voltage than 5V by changing resistor.
It would be nice to get somewhere flyer pinouts and see if it uses the same pins for 5V and 9V charging. If the same - it means that this car charger can charge flyer as fast as flyer mains charger just coupling data pins (now it has identifications circuitry for iphone -resistors between vcc,data,data,vdd). If not - it means that charger shoud be modified to deliver 9V and special cable with extra pins will be needed also.
you sure are going through a lot of contortions just to do same things that the HTC charger that comes in the box already does. Why not use the adapter made for the device?
I've got around 4 different micro-USB AC Adapters that I have lying around. One is the OEM Lenovo, One is OEM Samsung (i777 charger + Samsung Micro-USB cable), one is a multi-USB port AC adapter with a micro-usb cable, and the last is an iPad 2 wall charger with a micro-USB cable.
ALL of the chargers except the OEM Lenovo ones don't charge my tablet. When It's plugged in, for a couple of seconds it says Charging (AC), and then it just switches to discharging. I've tried all the aforementioned chargers and cables in different combinations, and the ONLY ones to work correctly is the Lenovo combo.
Is there a specific reason to this? Also tried all 4 cables connected to my PC.. They all don't charge efficiently at all.
look at the Voltage and Amperage of the adapter !
Lenovo use 2A if I remember well, the other use only 1A
quyTam is correct... most USB chargers are between 500mA and 850mA. The dual battery design of the tablets requires a min of 2A to charge correctly. This is why most computer USB ports will not charge the device.
However... the changer isn't the only thing restricting the power. The cable you are using can also effect power. Not all cables are created equal.
I stopped by Staples just after getting my tablet and picked up a 4 port 2.1A USB wall charger. It will charge my phone, Bluetooth, and tablet. There are also really nice 2A "extra battery" devices out there that allow you to a charged battery with you that will power and recharge your device.
I also recommend the dock for the tablet... it has a 65w power supply and charges the tablet in a 1/3 the time then the usb chargers.
where to get a charger
i tried 2Amp chargers....didn't help/
my brother says:
"the pins are slightly different/off/longer/shorter/what DID lenovo do here?"
as a safety i bought:
http://www.ebay.com/sch/?_kw=886605022780&_clu=2&_fcid=100&_fvi=1&_localstpos=&_stpos=&gbr=1
just in case...
it costs an arm and a leg for a microUSB charger, but not charging the device for a couple of days would cost me more :S
just another things that makes the TPT slightly less then perfect
o,O
Charger
I use a Dell Axim x51 charger and an LG cable from an old phone. Seems to work very well and eBay prices for the charger are less than $4.
http://rootzwiki.com/topic/8523-rev...arger/page__st__40__gopid__448194#entry448194
In my experience a 1A charger will also work. Nothing less than 1A will do anything.
I keep my Lenovo charger in my home office and use a 1A phone charger next to my bed for overnight charging.
I too have a 4 port mains to USB charger: 2A but I thought it was distributed to the 4 ports. If all were being used then each port would only be .5A.
Will have to try it out. If it works it would lighten the travel load of chargers.
Gottoon said:
quyTam is correct... most USB chargers are between 500mA and 850mA. The dual battery design of the tablets requires a min of 2A to charge correctly. This is why most computer USB ports will not charge the device.
However... the changer isn't the only thing restricting the power. The cable you are using can also effect power. Not all cables are created equal.
I stopped by Staples just after getting my tablet and picked up a 4 port 2.1A USB wall charger. It will charge my phone, Bluetooth, and tablet. There are also really nice 2A "extra battery" devices out there that allow you to a charged battery with you that will power and recharge your device.
I also recommend the dock for the tablet... it has a 65w power supply and charges the tablet in a 1/3 the time then the usb chargers.
Click to expand...
Click to collapse
That's for sure. I thought the dock was a waste of money until I forked out on Amazon. Saves so much time it isn't funny....
Sent from my Nexus S using xda premium
The tablet needs to see 5.3 V, when using >500mA.
Already thinner USB-Cables increase the voltage drop
so the thinkpad wont charge, even with the original charger.
It may have less to do with your charger than with the cables. I bought extra long (6 and 10 ft) USB cables for charging phone and my TPT. The 28AWG of any length won't charge the TPT. The 24AWG 6 ft and 10ft cable *will* on a 2A charger. I haven't tried other combinations. I believe it will charge on a 1A charger as well, but would likely require the larger 24AWG cable.
Sent from my PC36100 using Tapatalk
Design Flaw in Thinkpad Tablet prevents Landscape Mode Charging for Developers
I actually sent my 1838-22U in for service, thinking that there was a hardware problem preventing charging while connected via USB. At first I had noticed that while connected directly to a PC via USB for development purposes (no docking station), the unit indicated that it was charging. However, it seemed to be discharging faster than it was charging and slowly worked its way down to unusable. Lenovo Tech Support indicated that they had heard of this happening, and that I should send it in to have its system board replaced. I sent it in only to find that all they had done was replace the battery and reload the firmware. I did notice, however, that when I connected the USB cable, it appeared to go into charging mode for a couple of seconds then switch into discharge mode. I asked Tech Support about this and they said they this was actually the way it should have been behaving all along, and that this was by design.
The User Manual (see attachment) states only that it might not charge, and that it will only discharge if the tablet "exceeds USB 2.0 power limits" (i.e. 500ma).
Well, the Thinkpad Tablet seems to be pretty good at doing that.
Here's where I present to the development community a conundrum. How can one develop in landscape mode while charging (even slowly)? In portrait mode, one can use the accessory docking station, which uses its own charger and charges through the proprietary connector next to the micro USB port, while separately allowing the USB to be used for data. In landscape mode, there is no such option. I will accept that the unit may draw too much current to charge well via a 500ma USB data connection, but then Lenovo should provide a optional charger that connects directly to the same proprietary connector used by the docking station. This is done elsewhere. For instance, Motorola realizes that the Xoom draws too much current to charge via a USB data connection, so they don't even bother with it - they provide a dedicated charger connection and charger.
==UPDATE== 25-May-2012
SOLUTION FOUND
The solution to using a data connection and charging the Thinkpad Tablet at the same time, without relying on the portrait-mode-only Dock Station, is to connect through a powered USB hub which supports the USB Battery Charging Specification (with a Charging Downstream Port). The specification provides at least 1.5A, which quite handily satisfies the Thinkpad. I found such a hub, the GWCTech HU2V40, on Amazon for $15.99.
If you get this model, note that only one of the 4 ports can be used for high-current charging. It includes a tiny "Smart Charger Adapter" but which appears to block the data connection (at least when when used with the Thinkpad). In other words, ignore the little black passthrough adapter included with it, and plug directly in as you normally would. The instructions don't explain the purpose of the passthrough adapter.
Hi everyone!
I just wanted to ask this: I just bought a 90W charger for my laptop. It is a "Targus Compact Charger for laptop and usb tablet"
It charges my laptop and also has that usb port which charges through a cable, compatible devices. Only that on that usb port, it says that it charges 2.1A, which is a lot. My phone charger does only 550mAh.
So the question, shouldn't I charge my phone through the adapter?
Thanks in advance!
I recently purchased the Scosche reVOLT c2 dual usb car charger. Being 2.1A, I was hoping it would work with my new Prime. Unfortunately that is not the case. It's a nice product and works we with all my other USB devices, but no luck with the TF. Unless anyone has any ideas to make it work, avoid this if you are looking to charge your Prime.
-ajs
Even though most car chargers run off 12VDC input, they output only 5V for usb devices. The TF itself should trickle-charge with 5V, but in order to actually fast charge it (or charge while in-use), it requires [email protected] or more (give or take).
You need at least 12v output to charge the Prime at a normal rate. 15v is ideal. Standard USB is 5v.
+1 ^^ although I think I did read somewhere that the Prime will trickle charge on USB if it's off or "not in use"? Can't recall where I saw this...
Xxxxxxxxxxx
Yes, the Prime will charge on a standard USB port, but it will do so very slowly. I have done so myself.
Sent from my SCH-I500 using XDA App
Sorry, delete it.
I recently bought a scoche dual port 21W(dual USB with 2.1 amps per) charger that I thought could charge my 8.4 but it doesn't even seem to recognize it's plugged in. Is this because it needs that extra .3 volts from the stock charger? And are there any multiport chargers capable of charging this tablet?
I have 4-port charger from "Volmate" that I got from Amazon. Works fine. I don't see that same unit any more but they have a 5-port that looks similar:
http://www.amazon.com/5-port-Family...=UTF8&qid=1415848997&sr=8-16&keywords=volmate
The tablet doesn't need the .3 extra volts, it can use a variety of chargers as long as they are 5V 2A, it can even charge hooked to a PC , though the current from a computer would most like just be enough to power the device and not actually charge it.
Not sure why the tablet wouldn't recognize the charger you hooked up, does the battery icon have a X through it?
My Tab Pro can be used with many different chargers which sustain 2A or higher.
frentraken said:
I recently bought a scoche dual port 21W(dual USB with 2.1 amps per) charger that I thought could charge my 8.4 but it doesn't even seem to recognize it's plugged in. Is this because it needs that extra .3 volts from the stock charger? And are there any multiport chargers capable of charging this tablet?
Click to expand...
Click to collapse
It requires the D+ and D- pins shorted together with 1.2 V on them. Google "Charging your Smartphone from USB without fear" Sorry I can't post links.
I cracked open my car charger and changed out the resistors to 330k and 110k. It works now. The chargers that mention having a chip / IC like the Anker chargers with SMART IQ auto detects and works. The .3 V difference is to make up for the voltage drop of the cable, it isn't necessary but it lets it charge faster.
Fox9p3400 said:
It requires the D+ and D- pins shorted together with 1.2 V on them. Google "Charging your Smartphone from USB without fear" Sorry I can't post links.
I cracked open my car charger and changed out the resistors to 330k and 110k. It works now. The chargers that mention having a chip / IC like the Anker chargers with SMART IQ auto detects and works. The .3 V difference is to make up for the voltage drop of the cable, it isn't necessary but it lets it charge faster.
Click to expand...
Click to collapse
They're 33K (to +) and 10K (to -) resistors.
I made few of them so I can charge old type Tab and Note with iPad-like plug.
I'm not sure what this is all about... To charge my 8.4 I mostly use my 1.5A HTC One charger or an older LG 1A. On my boat I'm using a bog standard cigarette lighter USB charger with two 2A outlets (not more than 3A combined). I've never had any problems with any of these.
Why would I need one with shortened D+/D- pins (or do all chargers have this implemented?)