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hd2 rapid charge mod

anyone realise the original htc charger charges faster? especially now with those 4xusb port chargers.
i just did a simple test
test1
4xport 2ah + original htc cable = 150+mah
original charger + original cable = 800mah
test2
4x port 2ah + seagate dual usb cable but pluged in the 'power' cable + mini<->micro converter = 150+mah
original charger + same cable as above = 150mah
test3
4x port 2ah + seagate cable but the data usb head + mini <-> micro converter = 150mah
original charger + same cable + converter =800mah
i believe that the data pins are also supplying power aka pins 2 and 3.
i'm going to test pins2 and 3 with a multi meter when i get back to office.
i have tried 3 different brands of 4xusb chargers. only one of them charges @ 800mah.

please note that the hd2 implies constant voltage/variable current charging algorithms. This means that for a constant charge voltage of 4.2 volts, the charge controller will draw more current if the battery is at 10% then if it's at 90%.
Also, take note that the hd2 has 2 charging modes. The charge controller takes about 850-900mA at max. but as a standard usb port only supplies 500mA, the phone "senses" if it's plugged into a usb port and lowers the max drawn current to anywhere between 100-400mA in order to protect the usb port. The switching between the 2 modes is made by the presence of the usb data pins. If a voltage of about 0.9 to 1.7 volts is present on the data pins and GND, the phone thinks it's plugged into an usb port and will never draw more then 100-400mA. In order to charge as fast as possible, you need to apply power only to the Vcc and GND terminals, without connecting the data pins from the phone (2 and 3) to anything

Sent from my SGH-i917 using XDA Windows Phone 7 App

ok, tested, i soldered pin 2 and 3 on the charger. hd2 is now drawing 900ma

that's the most you'll get from it

Command to show charging current (sub-optimal when data pins not shorted together)

I found a sys file that contains the current in mA provided by the connected charger. I note that it is limited to a bit over 400 mA when the data pins of the usb connector are not connected.
The command:
Code:
cat /sys/devices/platform/i2c-adapter/i2c-0/0-0036/power_supply/battery/charger_current
entered either into the adb shell or a terminal gives the current being used from the charger measured in mA. When not connected to a charger (or the device is fully charged and isn't charging), this reads 0. When connected with an ordinary usb cable to the provided charger it reads about 750, except when the device is closed to charged. I'm not sure if this is a non-standard quantity but I am surprised to have not found this used in any monitoring ap; it seems like it would be a useful quantity to know.
I found an important caveat though. Originally the x10 would not charge when connected to a device that doesn't short the data pins together on the usb cable. (There are 4 pins on the microUSB connectors, 2 for power and 2 for data. When charging from charger or other such device the data pins aren't used to transmit data and should be shorted together as viewed by the X10) This meant that many commercially available car chargers and other such devices wouldn't work with the x10 without using a modified cable that would short such pins together.
The newer drivers (starting from around 2.1 update I think) allows this to work, but limit the charging capability to roughly 400mA when the data pins aren't shorted together. For example, I have an external battery which appears not to short such pins together. When I charge with this battery using a standard usb cable only about 400mA is used. However, if I use the cable provided with the battery, which I believe is modified so as to short those pins together (it clearly doesn't connect the data pins through as it has detachable connectors, and only 2 connections going into the detachable connectors) I find that the phone now uses 1000mA of power from the battery.
The same is true when connecting to a usb port on a computer. It draws about 400mA when connected with a standard cable, and closer to 500mA when connected with a cable that shorts that data pins together rather than connecting them to the data pins going into the computer.
Thus, when using a non-SE charger, car charger or external battery, it is a good idea to check the current being drawn using the above command. If it is less than the maximum expected for that charging device one might consider modifying a usb cable to short the data pins as seen by the x10 together (disconnecting them of course from the data pins facing the charging device).

[SHELL SCRIPT] Battery logging (discharge, capacity, etc)

USB to Barrel Cord / Barrel Specs? iGo Tip?

My goal is to not bring the A500 charger with me at all when I travel.
I just bought a refurbished iGo 90W charger at Fry's. I know if the correct tip was obtained it has plenty of juice to charge the tablet, but I'd rather use a USB solution and not hog a laptop charging port.
To accompany the iGo adapter, I'm thinking of purchasing a AC to multi-port USB adapter from monoprice.com (details below).
So although I'd have some USB to micro USB charging cables for cell phone, hotspot, gps, etc., (they have 1.5ft on monoprice.com), I will very much lighten my electronics charger and related cords load (and finally, charge the A500)
iGo Tip:
I have an ongoing Support Request with iGo regarding a tip for my A500 tablet. - I can update the thread when they respond. My charger uses the 700 series tips, it's the "slim" charger.
USB to Barrel Connector / Barrel Connector Details:
I'm not sure what the size of the barrel on the adapter is for the A500?. presumably this can't be too uncommon. On Amazon.com search for "usb to micro barrel" and tons of cables pop-up.
They have this USB AC adapter on monoprice.com (Product ID 8856 / http://www.monoprice.com/products/p...=10851&cs_id=1085102&p_id=8856&seq=1&format=2) that supplies a 2A charge to a single USB port designed for an iPad. I gotta think if I get the right USB to Barrel Connector cable it would charge the A500 well. I'm pretty sure a standard PC USB 2.0 spec port doesn't putout enough juice?
Any thoughts would be very much appreciated. I tried to comb the forum pretty exhaustively and I try and stay up to date anyway, so I'm not sure this information is really out there anywhere. I did notice the AC adapter thread http://forum.xda-developers.com/showthread.php?t=1856752, good news there!
-kg

Sorry to say: forget about it. USB spec is 5V 0.5A (most hubs allow up to 1A these days); Even if you had a way to step up the amps to the required 18W (that's 3.6A if you do the math), the tab still expects you to use 12V 1.5A... So you'd probably fry your tab. Your only solution thus would be a transformer 5V 3.6A -> 12V 1.5A. Now, I haven't checked this but I don't expect anything like this even exists and even if it does, it's probably so large you might just as well take the charger with you.
BTW: My measurements say the connector has a 3mm outside diameter and .75mm inside diameter. So if you can make your charger output 12V you're golden, as amps will be determined by the tab anyway. 90W means anything significantly above will trigger a fuse and shut the charger down -- or make it go up in smoke (possibly even blow up) if there's no fuse (if it's CE/FCC approved, it has one)...

haag498 said:
Sorry to say: forget about it. USB spec is 5V 0.5A (most hubs allow up to 1A these days); Even if you had a way to step up the amps to the required 18W (that's 3.6A if you do the math), the tab still expects you to use 12V 1.5A... So you'd probably fry your tab. Your only solution thus would be a transformer 5V 3.6A -> 12V 1.5A. Now, I haven't checked this but I don't expect anything like this even exists and even if it does, it's probably so large you might just as well take the charger with you.
BTW: My measurements say the connector has a 3mm outside diameter and .75mm inside diameter. So if you can make your charger output 12V you're golden, as amps will be determined by the tab anyway. 90W means anything significantly above will trigger a fuse and shut the charger down -- or make it go up in smoke (possibly even blow up) if there's no fuse (if it's CE/FCC approved, it has one)...
Click to expand...
Click to collapse
Thanks for the reply. So it seems the iGo tip is certainly still a possibility, i'm still waiting on them to get back to me.
While I am certainly not an electrician, I did find a thread here: Sorry it is on another forum and I don't have enough posts yet... It is titled Is "there a car charger for the A500" on androidtablets.net
They indicate that a 2000mA car charger from amazon works to charge the tab: Search for B0042X8XOQ on amazon.
Correct me if I'm wrong, but if that 2000mA charger charges the tab, wouldn't the proposed USB corded solution (with special 2-2.1A port) also work?
Thanks again!

[Q] USB charger resistors for 2A charging

Hi all,
When I'm on the go I am using a brick-sized 8Ah 12V Lithium-Polymer connected to a DC-DC converter (that can provide 5A at 5V) to provide charging for my devices. I've hooked up a USB port with shorted D+/D- wires to provide for fast charging on most devices, it works on my SGS2 to charge it at pretty much the same rate as a wall-charger.
However I got a 2A charger with my new SGS4 (i9505). Does anyone know the correct resistor values for telling the SGS4 that it can charge at the full 2A? And does it need any resistors from D+/D- to either +5V and 0 as well as the single resistor between D+ and D-?
I've searched a lot for this information but I can't find a definitive table of resistor values for various devices and current combinations.
Many thanks in advance,
Descore

http://forum.xda-developers.com/showthread.php?t=2274321

I need your help
Did anyone figure out the resistor values for the samsung galaxy tablets?
I have these on my walls connected to a main power supply. How can we tell the tablets to pull the full power?
Descore said:
Hi all,
When I'm on the go I am using a brick-sized 8Ah 12V Lithium-Polymer connected to a DC-DC converter (that can provide 5A at 5V) to provide charging for my devices. I've hooked up a USB port with shorted D+/D- wires to provide for fast charging on most devices, it works on my SGS2 to charge it at pretty much the same rate as a wall-charger.
However I got a 2A charger with my new SGS4 (i9505). Does anyone know the correct resistor values for telling the SGS4 that it can charge at the full 2A? And does it need any resistors from D+/D- to either +5V and 0 as well as the single resistor between D+ and D-?
I've searched a lot for this information but I can't find a definitive table of resistor values for various devices and current combinations.
Many thanks in advance,
Descore
Click to expand...
Click to collapse

%Mike Bax - Tesotronics 2018, Tested & Verified to work
%This is a Matlab script
%
%USB charging resistors resistors for Samsung Galaxy A0 tablet
%R1 to +5V, R2 to GND, center tap to Dx, for each dataline (so two voltage dividers),
% then short the center taps of both 2 networks
r2=22e3;
ui=5;
vb=1.23; %target voltage measured on original charger
r1=((r2*ui)-(vb*r2))/vb;
r1=68e3;
uu=(r2/(r1+r2))*ui; %check
%E12 approximation: R1 68k, R2=22k

Hard wiring for phone with USB-C and smart/fast charging?

Hey folks, so I've done the hard wiring of older phones with MicroUSB and <2000mAh charging before. It was pretty easy by just using a 12V to 5V 3A converter similar to what you see in the attached pic.
Now I want to do something similar for my Google Pixel XL which has a USB-C interface and does smart/fast charging.
Problem is, I'm unfamiliar with this tech and don't want to just wire it up without asking for advice first.
I'm thinking I'll be just fine using the same adapter you see in the pic below.
And I'm thinking I'll be just fine by using the two power wires and two ground wires from the USB-C spliced onto the 12v-to-5v converter.
I do not believe I need to worry about the fifth cable used for signaling between two devices.
So, from the USB-C connector, I would splice its two power wires to the single [out] power wire on the converter. And the two ground wires to the single [out] power wire on the converter.
Then the [in] power and ground on the converter would be spliced into my 12v harness of my car (or Motorcycle).
This should get me full speed charging just like my stock USB-C charger from Google.
Do ya'll agree or am I missing something that may screw things up?
https://hackaday.com/2016/04/22/hackaday-dictionary-usb-type-c/
Four of these connections are designated as VBUS connections, carrying the power for charging and operating connected devices. In addition, two pins are used for grounding, and one pin is used for signalling between the two devices to determine how much power should be sent. Running at the USB standard 5 V, the VBUS cables can supply up to 3 amps, a big increase on the 2 amps available in USB 3 cables, and much more than USB 2.
Click to expand...
Click to collapse
The 12V to 5V 3A converter I use:
post a picture