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Atom gets external power (backlight changes) but doesn't charge (DIY charger)

hi guys, I soldered a 5v charger's +5v & ground wires to a female USB port, then connected to the mini-usb port of the Atom, external power was detected but it doesn't charge, what else do I have to do to trigger charging? thanks!

ashy said:
hi guys, I soldered a 5v charger's +5v & ground wires to a female USB port, then connected to the mini-usb port of the Atom, external power was detected but it doesn't charge, what else do I have to do to trigger charging? thanks!
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Click to collapse
Interesting. I've noted similar issues, I first thought it was to do with the power current capacity however I'm not so sure now. What I did find was that if I plugged in the usb plug first and then turned the charger power on (e.g. car charger 850mA) then it would charge. However the original charger worked any which way. Also turning off the screen would result in slow charging even when it said not! Does this help?

There is some problem in oem battry driver, you can google to find the driver hotfix.
sorry for my BAD english..

You must give two other pins short with resistor as i remember. This is in order to simulate USB connectivity, which original charger do.
This is for HP Ipaq rw6815 I have..
more info you can find in below links it's for other devices, but the workaround is the same:
http://ecece.com/info/ipaqcradlemod/ipaqcradlemod.html
I don't think below method i safe enough, I think it's not a wise decision to shorten your data pins, but obviously work with iphone
http://carlhutzler.com/blog/2009/07/28/usb-hub-as-an-ipodiphone-charger/

How to speed up USB charging in Touch HD

I was always wondering how to speed up this unacceptably slow USB charging (If you are in a low signal area with bluetooth ON then the battery is drained far more quicker than the laptop can charge it ending up with a flat battery ). Finally I tested the output from the pins of the wall charger and my Laptop. Even when the laptop is powered off (no data exchange) the USB charging is very slow. The HD seems to send a ~1v pulse through D+ channel when to connect it to USB port (even when powered off the device seems to check if it is a USB data port), but with the charger it does not!, so we need to break this communication.
So I put a thin plastic film over the D+ and D- terminals of the USB cable and voila the device charges much faster..(slightly slower than wall charger - 25% slower, can be accounted for by the lower power output of the laptop USB port, the voltage of laptop usb port is 150-200 mV lower).
While I am typing this my HD has gained 9% charge with screen on!! . Natively it charged atmost 1% by this time with screen off.
Now I am looking for a permanent mod for my spare USB cable hacking off the data lines.
For those in a hurry with nothing but a HD with flat battery USB cable and a computer at hand, worthwhile using a thin paper over the inner two pins of the USB cable on PC side and plugging it in. (You do this at your own risk).
Hope it helps others too. Let me know your experiences.
With my Desktop USB port, charge rate is better than wall charger if you block the data pins. The port seems to be capable of 1.5 amp at 4.96 v
Also ensure that the USB cable snugly fits the mini USB port on HD.

Could this be also the problem why (my) Blackstone doesn't receive a TMC-signal with HyperGPS & iGO8 while charging in my car?
It's a genuine car charger from HTC, so I should say these pins are already "shut" from connection, or am I wrong?

I have a usb cable that is dedicatet for charging. It dosent have D+/- wires. With this cable on my laptop the charge time form about 20% is more than half of regular USD cable..
The cable was supplied with a car BT handsfree.
Regarding the TMC issue Im not shure, Try asking the guys that developed HyperGPS they might know, if not they might be able to fix if they arent aware of the issue

Interesting tip, thanks... I've lost my charger and have been finding it a pain to charge it using the USB port on my laptop.
I cut a small strip of paper from one end of a sticky note, and stuck the adhesive end to the outer flat surface of the USB plug to secure the strip in place. Seems to have done the trick, because the charging light is on and the PC hasn't detected the device. As for how long it takes to charge... will have to wait and see.
Also, I was wondering if there was any difference in charging speed (i.e. when charging via USB normally without using this trick) between activesync and file transfer mode?

Faster USB charging?

Just got a new motheboard which has high output USB charging for iPhones, pads etc.
Can this work on N1 ?
http://gigabyte.com/MicroSite/185/on-off-charge.htm
edit: driver link is at the bottom for all the hackers. Hopefully its just changing string from apple to android hehe

kazprotos said:
Just got a new motheboard which has high output USB charging for iPhones, pads etc.
Can this work on N1 ?
http://gigabyte.com/MicroSite/185/on-off-charge.htm
edit: driver link is at the bottom for all the hackers. Hopefully its just changing string from apple to android hehe
Click to expand...
Click to collapse
Hopefully not, I dont want my nexus one to be iphone.
But as you know nexus one is using qualcomm motherboard.
But aslong cyanogen and fm transmitter is working there is no problem wiith your phone.

Dear lord what a crappy reply. Stick to disney mate.

It should, it basically just converts the USB port from .5 amps to 1 amp, like a wall charger.

elkyur said:
Hopefully not, I dont want my nexus one to be iphone.
But as you know nexus one is using qualcomm motherboard.
But aslong cyanogen and fm transmitter is working there is no problem wiith your phone.
Click to expand...
Click to collapse
WTF??? May want to lay off the halucinogenics

elkyur said:
Hopefully not, I dont want my nexus one to be iphone.
But as you know nexus one is using qualcomm motherboard.
But aslong cyanogen and fm transmitter is working there is no problem wiith your phone.
Click to expand...
Click to collapse
lol I seriously hope this is a joke!
I agree with JCopernicus, it should definitely work.

I installed the software in the first post but it still charges very slow compared to wall outlet

Slightly OT, but I've got a USB adapter that plugs into the wall that came with my iphone and when I plug the N1 USB cable into this to charge the N1, it still charges very slowly compared to using the proper wall adapter, why is this? Does this iphone adapter restrict the voltage or something?

Generally, "charger detected" is a circuit that has USB data pins shorted together. So when the phone's USB device probes the lines and detects them shorted, it knows it's connected to a power supply.
But since USB max current spec is 500mA, the current draw is restricted - either by the phone or by the supply.
There might be some other connectivity trick that allows the phone to know it can draw x2 current from the socket and won't damage anything. Most phones probably don't limit the current draw and count on the board to do it. Some boards don't limit the current output, or limit it higher. And the fast chargers provide pulsing voltage - which isn't like USB.
So for the board to be able to charge the device, it needs to detect a device that can use pulsing voltage, and enable such voltage on the socket. It doesn't detect Nexus as such a device, I believe, and that's why the charging is slow.

Faster charging with USB
Building on Jack_R1's response, I believe that the phone is limiting the charge rate. You can make the phone "realize" it is connected to a charger rather than a data connection by shorting the 2 middle USB pins together. I have done this in several car chargers, and the N1 About/Status shows charging (AC), which is the faster charge mode. While you can short the pins in the larger end of a dedicated USB cable, if you can disassemble the connector, I found it much easier to open the charger itself to short the pins.

i also have a gigabyte mobo that has this feature but i havent gotten around to test it out yet. I dont think it would work because the feature is software based and will only bump up the voltage if the program detects an iphone connecting to your computer. Gigabyte doesnt want to be liable if they bump up voltage on every device you plug in and fry something.
btw I have tried charging my n1 from my computer and its extremely slow. started charging at around 5pm on sunday and at 11pm it went from about 23%-97% lol.

Yes, USB charging is very slow. It's actually good for the battery, though.

Maybe someone with some know how can look at the driver files for this 3x tech and see how it checks if its an Apple device. Then fool the check and presto!
Shame I don't know how to do any of this

There is a simple hardware (don't worry, it's on the cable) mod for faster charging; however, make sure the phone has good air vent (it means NO CASE when charging).
1. modify your microUSB cable, disconnect the data connector the A (host) plug, then shorten the data connector to the B plug. (This can charge N900 properly, and speed up n1 charging).
2. modify your powered (with AC adapter plugged) USB hub. Simply shorten the #2 and 3 connectors on USB jack. Make sure you cut the copper strip going to the chip or malfunction may occur.
These modification can greatly speed up the charging, but phone will produce a lot of heat (that's why you must have the phone "naked").

I don't understand this. If the phone + battery are capable of being charged at 1000 mAh from the wall charger then why need extra cooling when asking for 1000 mAh from a PC USB socket?
Mine's still defo getting only 500 mAh from the PC USB despite it being able to give up to 2700 mAh for iPad!!! All I want is my 100 mAh charge.

Because what he suggests isn't a proper charging but rather removal of slot power control, and will damage the battery / phone, if succeeds.
Proper charging at 1000mAh requires pulsing voltage - his hack doesn't provide that. Your MB does, but it requires SW intervention to turn it on.

So can someone brew the intervention ?

martinl1030 said:
i also have a gigabyte mobo that has this feature but i havent gotten around to test it out yet. I dont think it would work because the feature is software based and will only bump up the voltage if the program detects an iphone connecting to your computer. Gigabyte doesnt want to be liable if they bump up voltage on every device you plug in and fry something.
btw I have tried charging my n1 from my computer and its extremely slow. started charging at around 5pm on sunday and at 11pm it went from about 23%-97% lol.
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Click to collapse
They are not doing anything to the voltage, simply allowing more current to pass.
And as said in this thread, any typical data USB cable will charge very slowly. And most standard USB ports charge well less than the max specced 500mAh, in fact my subnote at work I found charged my old phone at around 150mah one time when I was dead and needed to top off and it's all I had available.

i'm not sure of the pinout on the micro USB port but i'm pretty sure that that the Mini USB-B port that was used on phones like the G1 used shorting the -Data pin to the unused 5th pin (actually pin 4 on the connector pinout) to activate AC charge mode. some devices actually require a resister of a certain value to be placed across them to work(i know older motorola phones did like IDEN's)
one thing people often forget but should not forget is that current is drawn from the device using power. its not forced on the device. voltage is forced on a device and while a variance is usually ok for devices depending on how they were designed generally its not a good idea to exceed +1.5v on any low power DC device. 120V AC devices are designed to actually work in a much wider range like 100-130V but thats because of the power supply/nature of AC power. it always varies and in japan they use 100v 60hz AC so many electronics power supplies are designed to work in the full range to save costs and only have to make 1 unit for all (same deal with 220-240 switches on PC power supplies)
the reason why you don't want to do this mod is you could damage you PC's motherboard by pulling too much current from its circuits. USB spec is 500ma. performing this type of mod on a power adapter (car or AC) that does not get recognized as an AC charger by the phone is a safer way to go. worst case senario is you break the charger (unless you mess up on the pinout then you could damage you phone too though)

Possible USB OTG Power collision in hub ?

Hi everyone!
Firstly I am not sure if this is correct forum, but its only one related with hardware...
I has built my own emergency charger powered with solar energy.
It can provide 5V with 2A max. (about 10W) and provides two USB ports for devices.
Althought I dont have any phone/tablet with USB OTG (Host) function, I d like to prepare it to provide all this functions:
- charge two client devices
- charge two host devices
- charge one host and one client device
But, there is one problem with power - some OTG devices provides power, and some not.
Thats the thing, why I am asking - if both chargers connectors are powered and one host device is connected in it there will be a power collision - on one wire will be 5V from both sides - from e.g. phone and from charger. This will surely damage the phone because of shortcut.
I am right? Or, is a hosts power enabled, only, if there is not any external power plugged?
Hope, that anyone will understand, I can also provide a schematics later it it could help
Thanks anyone !!!

The wire is the same, so there won't be any collision, it doesn't matter where the voltage source point is when it's applied on the same wire (without any component in between the voltage sources).
I guess maybe the only thing will happen is that the phone battery won't have much or perhaps even no drain?
And speculating here on same line of thought, dunno exactly how the charging circuits work on the phone, but i guess it won't charge when in OTG mode even with an external power power source available...

My Touchpad doesn't provide OTG power but refuses to charge when in OTG mode, maybe other devices are different though. OTG will still work on it even if I disconnect the +5v Vcc (red) wire. If you wanted to force USB devices to be powered from the external supply maybe you could try disconnecting Vcc from the device.

Thanks - more people, more ideas,more knowledge
As told - there are two kinds of OTG devices - self powered (few Xperia`s and Samsung devices) and non powered (spunkler88`s Touchpad and e.g. my Xperia X10i).
In case of non powered devices, there shouldn`t be any problem, think that host just won`t accept power and nothing bad happens. But in case ot self.powered devices there is in OTG mode voltage on vcc pin - 3,3 or 5V (low power or high power mode).
I`m not so demanding to want host and slave to be charged at the same time.
We dont have to worry about non powered host devices, but afraid about powered ones... Or even if we don`t know, if our device is powered or not
Elusivo:
I know, that it is the same wire You maybe didn`t caught my point - there could be two power sources on one wire - one could be phone (in OTG mode) and one power on hub.
Will post an scheme as soon as possible.

HeliumX10 said:
I know, that it is the same wire You maybe didn`t caught my point - there could be two power sources on one wire - one could be phone (in OTG mode) and one power on hub.
Will post an scheme as soon as possible.
Click to expand...
Click to collapse
Yes, actually there shouldn't be any issues with this now that I think of it. The phone if providing powered USB OTG would simply act as a parallel voltage source with the charger meaning voltage stays the same and the available currents add.

So, there is the block diagram of device which i have built:
The red cross indicates the one wire collision when DEVICE B provides power. If device B doesn`t provide power there won`t be any problems surely.
But as I thought of it, there is no solution for it - parallel voltage will surely damage one device on one side. The power sources providing high-efficient PWM power has very very low input resistance. So if we connect any voltage to its output, very high current will flow throught and surely damage the power source. This can happen very easily, because from phycisict`s point of view the higher voltage source will damage the less voltage source (there is +/- 10% tolerance on USB power, so this could happen everytime).
So now I am thinking about some mosfet auto switching circuit, which could automatically connect or disconnect power from master device... Or maybe will simple add an switch which will disconnect the power from master device everytime and power just a slave.

< wrong posting removed >

It doesn't pay to overthink this.
These devices are usually designed to take a beating.
Just connect all the Vcc's together.
I've been using something similar on my B&N Nook Touch for months.
It's not a solar charger, but a modified $10 USB hub.
I can use USB host mode on my Nook and charge at the same time.
Of course, all the peripherals are powered off the hub power supply too.
A general schematic is attached, pull the diode and insert a jumper.
Since USB was really not designed to charge in host mode,
there are two problems related to getting the device charging circuit to play nicely.
When using host mode to directly power a peripheral you must make the device charging circuit go off.
To go into host mode the device must raise the Vcc line to 90% of 5V, i.e. >4.5V.
If the device charging circuit is still enabled it will try to charge itself using itself!
When using host mode with incoming power the device charging circuit must be convinced to charge.

Renate NST said:
It doesn't pay to overthink this.
These devices are usually designed to take a beating.
Click to expand...
Click to collapse
Yeah, mostly yes, but dont want to try if this is also for all devices. Most of them could take beatings,some not... So trying to design absolute save solution
Renate NST said:
A general schematic is attached, pull the diode and insert a jumper.
Click to expand...
Click to collapse
See that, diode is used as blocking diode, which prevents shortcut So VCCs cant be connected together without protection. It seems that is for case I spoke about power provided from OTG device....
So as I see, simpliest solution will be the best. I will add a switch at the output for one USB ports VCC wire. And if I will use my charger as host active hub, will disconnect power (with switch) to one port, second port will be powered all the time. When charging two slave devices, i could switch power back too to the second USB port.
Renate NST said:
When using host mode to directly power a peripheral you must make the device charging circuit go off.
To go into host mode the device must raise the Vcc line to 90% of 5V, i.e. >4.5V.
Click to expand...
Click to collapse
OK, mainly thankx for this lines, once it happened that my phone indicated, thats chagring, but battery ran down.... Thought that was some kind of software relaed thing....

Hi Renate,
I've read and re-read your points several times and I think I understand.
My goal is to put together a battery powered USB Hub that also charges the phone at the same time. From your points, the B&N Nook is capable of going into Host mode while still accepting a charge - do you believe this to be true of most/all devices?
Did you have to do anything to get the Nook to charge in host mode other than supplying power by putting a jumper in lieu of the diode?
What $10 powered USB hub did you use?
Sorry for all the questions.
Renate NST said:
It doesn't pay to overthink this.
These devices are usually designed to take a beating.
Just connect all the Vcc's together.
I've been using something similar on my B&N Nook Touch for months.
It's not a solar charger, but a modified $10 USB hub.
I can use USB host mode on my Nook and charge at the same time.
Of course, all the peripherals are powered off the hub power supply too.
A general schematic is attached, pull the diode and insert a jumper.
Since USB was really not designed to charge in host mode,
there are two problems related to getting the device charging circuit to play nicely.
When using host mode to directly power a peripheral you must make the device charging circuit go off.
To go into host mode the device must raise the Vcc line to 90% of 5V, i.e. >4.5V.
If the device charging circuit is still enabled it will try to charge itself using itself!
When using host mode with incoming power the device charging circuit must be convinced to charge.
Click to expand...
Click to collapse

zuberio said:
From your points, the B&N Nook is capable of going into Host mode while still accepting a charge - do you believe this to be true of most/all devices?
Click to expand...
Click to collapse
I will answer these lines
Nook can charge when in host mode. But some new devices form Sony and Samsung cant,because they are providing power to hosted device. And if you connect active hub to them in host mode, you will damage the phone - thats why I opened this topic, but I solved it with simple diode indicator and switch (manually disconnects power to the phone if it provides power itself).

zuberio said:
What $10 powered USB hub did you use?
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Click to collapse
I just meant any generic hub. They are all about the same.
Usually the input diode is easy to identify.
Often it's the physically largest device present.
If you want, post a good photo.
The 4 port ones have one chip, 2 for 7, 3 for 10, 4 for 13.
I've never seen/heard of a hub chip with more than four outputs.
Yes, the USB spec does say only four outputs, but that's for unpowered hubs.
The spec for all the device USB chips have a maximum recommended of 7V on the lines.
I don't lose any sleep putting my 5V in.

Thanks for warning me off just going out and applying Vcc to my phone in host mode without first testing if it supplies it's own power.
When you say diode indicator do you mean an LED? And if the LED lights up you flip a switch to disconnect the hub power to the phone?
HeliumX10 said:
I will answer these lines
Nook can charge when in host mode. But some new devices form Sony and Samsung cant,because they are providing power to hosted device. And if you connect active hub to them in host mode, you will damage the phone - thats why I opened this topic, but I solved it with simple diode indicator and switch (manually disconnects power to the phone if it provides power itself).
Click to expand...
Click to collapse
---------- Post added at 07:42 PM ---------- Previous post was at 07:31 PM ----------
Ah, I understand now.
I guess the safest option for my battery backup/powered usb hub device is to install a 'mode' switch. Either it's a battery backup, or it's a battery powered USB hub - depending on the 'mode'.
Now I just need to hunt down a cheap powered USB hub and a battery that will power it or my phone.......
Actually, would there be any issues using an inline powered USB hub and disconnecting the Vcc from the host side to instead attach to a 5V 1A power source? The power source could probably be two minty-boosts in parallel.
[EDIT] Doh, I looked again at your hub.jpg - I just need to use a powered USB hub setup like that with a switch to bypass the diode for the 'phone charge mode' mentioned above (probably with some special resistances between D+ and D- depending on the device).
Renate NST said:
I just meant any generic hub. They are all about the same.
Usually the input diode is easy to identify.
Often it's the physically largest device present.
If you want, post a good photo.
The 4 port ones have one chip, 2 for 7, 3 for 10, 4 for 14.
I've never seen/heard of a hub chip with more than four outputs.
Yes, the USB spec does say only four outputs, but that's for unpowered hubs.
The spec for all the device USB chips have a maximum recommended of 7V on the lines.
I don't lose any sleep putting my 5V in.
Click to expand...
Click to collapse

zuberio said:
(probably with some special resistances between D+ and D- depending on the device).
Click to expand...
Click to collapse
No, resistors between D+ and D- are only for charging devices that are not communicating.
If you want to charge and communicate then you have to leave those alone.
That's why I said that you may need a kernel driver mod or an app to turn on charging when communicating.

I agree and understand - I guess I wasn't very clear in my last post.
My device will have two separate modes.
Mode 1:
Battery powered USB hub that doesn't provide power upstream to the OTG host device.
Mode 2:
Battery backup power device - powered USB hub disconnected
Such a device would be compatible with all Android devices, regardless of weather they provide power in OTG Host mode or not
Renate NST said:
No, resistors between D+ and D- are only for charging devices that are not communicating.
If you want to charge and communicate then you have to leave those alone.
That's why I said that you may need a kernel driver mod or an app to turn on charging when communicating.
Click to expand...
Click to collapse

zuberio said:
I agree and understand - I guess I wasn't very clear in my last post.
My device will have two separate modes.
Mode 1:
Battery powered USB hub that doesn't provide power upstream to the OTG host device.
Mode 2:
Battery backup power device - powered USB hub disconnected
Such a device would be compatible with all Android devices, regardless of weather they provide power in OTG Host mode or not
Click to expand...
Click to collapse
I understood clearly
This is the exactly the same I made completely myself. It has only 2 ports (no active chip, simplier and more reliable solution). It has One connector only for OTG master and second one port is for host device. When switch is on, power is also delivered into OTG host port, otherwise poered are all of the slave ports. But mine is designed mainly as emergency charger (for OTG Master device or two slave only phones/devices), or as active hub (thats why I added the switch with resistor and diode as power check).
Will post a diagram if you want.

prie irgseha
My touchpad is not power OTG, but refuses to load when the OTG mode, other devices will be different. OTG still working on it, even if I disconnect Vcc +5 V (red) wire. If you force, the USB devices be powered by external power supply might try unplugging the device Vcc.

BC1.2 Usb battery charging specs
Hi All,
I see that the last post here is a month ago, but here goes anyway. I am looking to do the same thing - I want to hack a 4 port powered USB hub to also charge the host (upstream) device.
Two modes of operation shouldn't be required. The specs allow for the phone to act as the USB host, and simultaneously charge. A powered USB should be easy to hack to simultaneously charge the phone and give you a useable USB hub for keyboard/mouse/usb stick or high-powered devices you can't use directly on the phone like USB hard disks.
I've made a reasonably close study of the Battery Charging Specification rev 1.2 (dec 2010) (USB implementers forum). The relevant sections and diagrams are around section 6.3: Standard ACA (accessory charging adapter) which could be a modified 4-port powered USB hub, hacked to be an "Accessory Charger Adapter" (figure 6-1):
1. The charger port should be 5V; jump that to the 5V V+ pin on the "OTG Port" - the OTG port would be the USB upstream port on the hub.
2. An ID resistance needs to be fitted integral to the μ-A Plug connecting to the OTG device, 124kohm between the ID pin and GND. (ref table 5-3 Resistances: RID_A; table 6-2 row 6)
I won't be able to use it anywhere else, because of the short to the V+ pin I've put there, but I would then have a battery charger for my phone which simultaneously works as a 4 port hub.
I have a Galaxy Note N7000. Does anyone know if this is FULLY compliant with the above referenced BC1.2 spec? I wonder because the Note also does audio and HDMI out on that port. Presumably with non-standard Rid values at the connector end.

Different hardware supports different ID pin sensing and data pin multiplexing.
On the Nook Touch, which uses a TPS65291, ID sensing is just short/open.
There is ability to use UART through the ULPI interface, but I haven't noticed it.
Many devices have separate muxes to integrate MHL, UART, CarKit (audio) and USB.
The CarKit is the tricky one because the signal goes below ground.

scitobor said:
I have a Galaxy Note N7000. Does anyone know if this is FULLY compliant with the above referenced BC1.2 spec? I wonder because the Note also does audio and HDMI out on that port. Presumably with non-standard Rid values at the connector end.
Click to expand...
Click to collapse
I suspect that the N7000 is very similar in Specs to the I9100, and thus it is more likely that it conform to the BC1.1 as mentioned and linked in this thread/post here. Remember that HDMI (and possibly audio) is not covered by the BC specs and very manufacturer dependent.

Shorting the USB Port?

I bought a Nexus One with the infamous broken power button issue, and I am curious what would the effect be if I short the VCC and GND line in the charging port? Has anyone tried that? I am thinking that it will either fry the board or trick the phone to think that it is charging.
The reason I want to do this is because I travel a lot and I might not have access to USB charging if I want to swap the SIM card. I am familiar with the other tricks regarding remapping the trackball_center and I am going to install a version of CWM that doesn't support charging (that way the phone boots when I plug a charging cable).
So long story short... what do you think about attempting to short the micro USB charging/data port?

dcalpha said:
what do you think about attempting to short the micro USB charging/data port?
Click to expand...
Click to collapse
Not much.
Unless the unit is in USB host mode there will be no voltage on the Vcc line.
Even in USB host mode it should be current limited and do no damage.
Still, I wouldn't do it.
I don't know why you think that shorting it will do something useful.

Renate NST said:
Not much.
Unless the unit is in USB host mode there will be no voltage on the Vcc line.
Even in USB host mode it should be current limited and do no damage.
Still, I wouldn't do it.
I don't know why you think that shorting it will do something useful.
Click to expand...
Click to collapse
I actually do not know, thus I asked... just trying to think outside the box about a way to trick the phone to think it is charging short of carrying a portable battery charger with me (which can be problematic on carry-on luggage).

Another idea I am thinking about is building a small flex cable using a conductive ink pen that permanently connect to the phone's battery on one side and a cut down male micro-usb on the other side (to slim it down). Such cable would be small enough to fold under the battery cover and allow it to close.
My question is: Will the ~3.7v be enough to get the phone to start charging? and do you foresee any issues with feeding power from the battery right back into the phone's charge port?

dcalpha said:
Another idea I am thinking about is building a small flex cable using a conductive ink pen that permanently connect to the phone's battery on one side and a cut down male micro-usb on the other side (to slim it down). Such cable would be small enough to fold under the battery cover and allow it to close.
My question is: Will the ~3.7v be enough to get the phone to start charging? and do you foresee any issues with feeding power from the battery right back into the phone's charge port?
Click to expand...
Click to collapse
I think 3.7 won't be enough. Coz usb giving ~5V. So phone won't charge at smaller voltage.