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[Q] Touchpad charging at 100ma only

Hi there, long time lurker first time poster as I cant find this problem anywhere and my googlefu has failed me.
Background:
I have a HP Touchpad 32gb, Ive been running CM9 recently.
A month or two into first getting the touchpad I had problems turning it on (assumed battery problem) and got it fixed through HP warranty, returned the same device in working order, non the wiser about what went wrong.
Onto the problem at hand:
Nearly a year later the battery appears to go below safe capacity and wont turn on at all no matter the button combination used or charge/discharge tricks/chargers.
Resorted to taking apart, removing and charging the lipo battery with a RC battery charger and SUCCESS! powers up 100% battery etc.
HOWEVER now no matter what charger or cable combination I use the battery will not charge, webos claims that I am not using the official charger yet I have tried 2 official chargers and many micro usb cables to no avail.
Using JCSullin's TPChargeTest-v1.0 application displays that the device is only receiving 100ma charge using official charger and 0ma (!!) when charging from usb host.
my next guess is that the battery is dead/dying and need a new one, but before I shell out and wait for delivery of a battery I was wondering if anyone had any similar problems or perhaps a suggestion on how to fix this?
Thanks :good:

I have left the charger plugged in with the touchpad off for 24h+ and the battery has gone from 93% to 50% in that time. The battery is clearly not charging.
Does anyone have anything I could try?

If its the battery port, you can try to get a Touchstone charger, which will eliminate the need for a charging cable. If its the battery, the only thing you can really do is try and replace it if you know how. And you are charging it in a wall outlet right? Not a computer? Because a computer wont charge it.

Having exact same problem with my touchpad which previously was charging fine off the original ac charger.
Left it charging with wifi & screen off, went from 11% to 25% in a little over 8 hours ... Not good!

Ok, further update ...
Have swapped over the usb board with another TP brick. Its now charging at the recommended 2A from the wall/mains charger.
So ... best guess seems to point to the usb port/board being faulty. Guess the only option with that is to do what I did or use a wireless charger.
Peace
Edit - a further hint that it was the usb port, was that I could not get it recognised when plugging into pc or laptop. Not in any mode, shape or form...

I had the Usb board replaced while it was still under warranty. Your lucky (sort of) that you had a spare.

Aye, lucky! It's a tp that is totally resistive to any attempts at resurrection, even tpdebrick can't touch it! So it is serving another purpose, as a donor!
I guess a touchstone would have done but file transfer was gonna prove difficult ... the damaged USB port meant my pc could not understand what the hell was being plugged in ...

chris5s said:
Ok, further update ...
Have swapped over the usb board with another TP brick. Its now charging at the recommended 2A from the wall/mains charger.
So ... best guess seems to point to the usb port/board being faulty. Guess the only option with that is to do what I did or use a wireless charger.
Peace
Edit - a further hint that it was the usb port, was that I could not get it recognised when plugging into pc or laptop. Not in any mode, shape or form...
Click to expand...
Click to collapse
Sounds like a similar problem to me! I shall have a look for parts online. Might try a new battery aswell.
Thanks!

alowva said:
Sounds like a similar problem to me! I shall have a look for parts online. Might try a new battery aswell.
Thanks!
Click to expand...
Click to collapse
Out of interest, what happens when you connect to a pc with the USB cable? Is the device recognised? If not, likely the USB port is u/s and a new battery might be an unnecessary expense ... Just a thought.
Peace

chris5s said:
Out of interest, what happens when you connect to a pc with the USB cable? Is the device recognised? If not, likely the USB port is u/s and a new battery might be an unnecessary expense ... Just a thought.
Peace
Click to expand...
Click to collapse
Excellent idea! I have checked on android and webos and neither are detecting a USB connection to my PC, but it does detect as "charging" however Touchpad Charge Test still shows its charging at 0ma
I thought it might have been the port assembly that was broken, and I checked to see if it was seated properly where it connects to the motherboard and it seemed to be, perhaps a the data+ or - has been broken, I shall inspect it closer and maybe get out the multimeter.
Thanks for the idea, hopefully i can fix this without getting a new battery! :good:

I have checked the micro USB port on the TP and it seems that the data connections and even possibly the power connections aren't working.
Im going to attempt to resolder them before getting a replacement as they're hard to find and expensive (In in the UK) hopefully that will fix it.

alowva said:
Hi there, long time lurker first time poster as I cant find this problem anywhere and my googlefu has failed me.
Background:
I have a HP Touchpad 32gb, Ive been running CM9 recently.
A month or two into first getting the touchpad I had problems turning it on (assumed battery problem) and got it fixed through HP warranty, returned the same device in working order, non the wiser about what went wrong.
Onto the problem at hand:
Nearly a year later the battery appears to go below safe capacity and wont turn on at all no matter the button combination used or charge/discharge tricks/chargers.
Resorted to taking apart, removing and charging the lipo battery with a RC battery charger and SUCCESS! powers up 100% battery etc.
HOWEVER now no matter what charger or cable combination I use the battery will not charge, webos claims that I am not using the official charger yet I have tried 2 official chargers and many micro usb cables to no avail.
Using JCSullin's TPChargeTest-v1.0 application displays that the device is only receiving 100ma charge using official charger and 0ma (!!) when charging from usb host.
my next guess is that the battery is dead/dying and need a new one, but before I shell out and wait for delivery of a battery I was wondering if anyone had any similar problems or perhaps a suggestion on how to fix this?
Thanks :good:
Click to expand...
Click to collapse
Hello @alowva,
I know it's been a long time since you posted this.
Do you remember what pin did you plugin your LIPO charger?
Did you use nicad?
I have a very low battery I need to boost.
Thanks a lot

pas7771 said:
Hello @alowva,
I know it's been a long time since you posted this.
Do you remember what pin did you plugin your LIPO charger?
Did you use nicad?
I have a very low battery I need to boost.
Thanks a lot
Click to expand...
Click to collapse
Well this is a blast from the past...
I eventually gave up on this tablet, but not before soldering a usb cable directly to the charging board to get a little more life out of it!
However since then I have had plenty of experience with other phones, tablets and laptops, and bare 18650 liion cells recharging and reusing for other projects.
WARNING! DO THE BELOW AT YOUR OWN RISK, I TAKE NO RESPONSIBILITY FOR YOUR ACTIONS.
I would recommend taking out the battery from the tablet (which is possible to do without completely dissasembling if you're careful enough)
Once removed the battery itself has a 7 pin connector, the outside wires 2x red (positive + ) and 2x black (negative - ). check the voltage on the battery using a voltmeter, "healthy" voltage is between 3v and 4.2v, if its below 3v you may have issues depending on the charger and if the battery is internally damaged.
The easiest way to connect to a charger is to use some solid core wire (or paperclip) pushed into the white connector on the battery, one wire connecting both red cables, and another connecting both black cables. then connect those wires to the red (positive + ) and black (negative - ) cables on your charger.
Charge at a slow rate and and be careful not to connect red to black!
Make sure you dont leave the charger and battery on anything flamable, a concrete floor or baking tray might help, and keep an eye on it as if the battery is internally damaged it may swell and catch fire (search for videos of lithium battery fire)
I have had a lot of success with reviving batteries in this way, however its best to be safe!
EDIT: dont use NICAD charger, only liion or lipo charger

alowva said:
Well this is a blast from the past...
I eventually gave up on this tablet, but not before soldering a usb cable directly to the charging board to get a little more life out of it!
However since then I have had plenty of experience with other phones, tablets and laptops, and bare 18650 liion cells recharging and reusing for other projects.
WARNING! DO THE BELOW AT YOUR OWN RISK, I TAKE NO RESPONSIBILITY FOR YOUR ACTIONS.
I would recommend taking out the battery from the tablet (which is possible to do without completely dissasembling if you're careful enough)
Once removed the battery itself has a 7 pin connector, the outside wires 2x red (positive + ) and 2x black (negative - ). check the voltage on the battery using a voltmeter, "healthy" voltage is between 3v and 4.2v, if its below 3v you may have issues depending on the charger and if the battery is internally damaged.
The easiest way to connect to a charger is to use some solid core wire (or paperclip) pushed into the white connector on the battery, one wire connecting both red cables, and another connecting both black cables. then connect those wires to the red (positive + ) and black (negative - ) cables on your charger.
Charge at a slow rate and and be careful not to connect red to black!
Make sure you dont leave the charger and battery on anything flamable, a concrete floor or baking tray might help, and keep an eye on it as if the battery is internally damaged it may swell and catch fire (search for videos of lithium battery fire)
I have had a lot of success with reviving batteries in this way, however its best to be safe!
EDIT: dont use NICAD charger, only liion or lipo charger
Click to expand...
Click to collapse
Thanks for your explanation..
I have seen videos on Lipo battery revival.
mine is at 2.540v I will use a Lipo B6 charger, some people said that slow charging in nicad or nimem mode because on lipo mode it will show a low voltage.
I do have a lipo fireproof bag.
Do you know what the blue, yelow and green wire do?
Thanks
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help , need a y spliter that works?

Please do not reply unless you know it works and where to get one? I have been buying them all over the place and none work?
maybe I dont understand something?
First I have a rooted unlucked nexus 7 with a OTG cable that works fine with stickman and many devices. Though to power my external HD I need to steel some more power. So I bought 5 now, y splinters only to find they dont allow current to flow from USB port to either my HD or nexus.
Y splitter- 3 ends.
1) a normal USB type A ( this plugs in to my normal usb source NOT A HUB )
2) a normal USB type A female ( this is where my usb devices get connected )
3) a micro ( has other names ) ( plugs in to my nexus 7 )
Ok so if I plug in the 1 to my USB port and 3 to my nexus, no charging?
also
If I plug in the 1 to my USB port and 2 to my device, not enough power.
and
If I plug in the 1 to my USB port and 2 to my device, 3 to my nexus, no charging and the HD does not have enough power.
Though not using the y splitter cable from computer to HD works fine. I dont see why the splitter would not deliver the same power especially when the nexus is not connected to it.
I know the HD works on my computer.
So short of making a cable, where can I buy one that does this?

ulao2 said:
Please do not reply unless you know it works and where to get one? I have been buying them all over the place and none work?
maybe I dont understand something?
First I have a rooted unlucked nexus 7 with a OTG cable that works fine with stickman and many devices. Though to power my external HD I need to steel some more power. So I bought 5 now, y splinters only to find they dont allow current to flow from USB port to either my HD or nexus.
Y splitter- 3 ends.
1) a normal USB type A ( this plugs in to my normal usb source NOT A HUB )
2) a normal USB type A female ( this is where my usb devices get connected )
3) a micro ( has other names ) ( plugs in to my nexus 7 )
Ok so if I plug in the 1 to my USB port and 3 to my nexus, no charging?
also
If I plug in the 1 to my USB port and 2 to my device, not enough power.
and
If I plug in the 1 to my USB port and 2 to my device, 3 to my nexus, no charging and the HD does not have enough power.
Though not using the y splitter cable from computer to HD works fine. I dont see why the splitter would not deliver the same power especially when the nexus is not connected to it.
I know the HD works on my computer.
So short of making a cable, where can I buy one that does this?
Click to expand...
Click to collapse
Are you sure you can charge it with an OTG cable? My Nexus 5 won't charge with OTG cable, but my Nexus 7 with OTG+charge kernel charges fine.
Sent from my Nexus 7 using Tapatalk

GrandeParade said:
Are you sure you can charge it with an OTG cable? My Nexus 5 won't charge with OTG cable, but my Nexus 7 with OTG+charge kernel charges fine.
Click to expand...
Click to collapse
I found a thread ( lost it ) that said it depends on the wiring used. This does make sense to me, I guess it depends on shielding and thinness of the wires internally. If the phone/tablet does not sense enough current it wont charge. That said, any thinker cable y splitter should work. I dont know about the 5, I have a 4 I could test on. But I know for a fact these cheep cables I have do not charge a damn thing.
Side note, the cable should not have any active electronics in it. So there is no way it would know a 4 from 5 from 7? I'm not doubting what you say but that is quite confusing. I'll try it on my 4 when my battery drops a bit.
When trying to charge my 4 it says charging but does not really charge.
How thick is your y-cable ?

i was able to make one of my cables charge my phone but it will not charge my nexus 7.

While I can't explain this technically, this doesn't work with a stock rom. Timor kernel is the only I tried which allows both. I ended up using a pogo workaround.

I think this explained it best
Fast charging while in USB host mode
Fast charging allows your N7 to draw up to 1800 mA (instead of up to 500 mA) from the attached power supply, while in USB host mode. Despite the name of this optional feature, it's main purpose is not to charge your battery faster (it will do this, too), but to allow the system to fetch more energy, while in heavy use. When fast charging is activated, the system will have less need (or no need at all) to make use of battery power, for it's runtime operations. Your battery will also reach 100% charge faster. But once there, the system will switch to trickle charging, despite the 1800 mA it is allowed to draw.
Click to expand...
Click to collapse

No this is all dead wrong.. Ok here is the deal. first this
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know it, understand it, get it.
Now its near impossible to meter these mico cables so the easy way to test it is by testing with a flash drive. So if you plug a cable in to the tablet and then a flash drive ( and the drive shows up on stickman or whatever ) you got a OTG cable. If its not a OTG cable its a normal usb and will charge the device.
I was able to find, in the mix of my cables, a way to get my set up.
Mirco from tablet ----> split to a female micro and normal usb female.
---> the micro gets power from a normal usb charger.
---> the normal usb goes to a hub and powers my devices from that usb charger.
Caveat here is that the tablet will not charge. To fix this you need a new kernel. or a wireless pad Works like a charm for me.

Technical details about nook HD+ charging

As an engineer I pulled some info from the datasheet for the chip the nook uses, it may help better understand charging issues.
full datasheet is on the TI site at:http://www.ti.com/lit/ds/symlink/bq24196.pdf
USB Timer when Charging from USB100mA Source
The total charging time in default mode from USB100mA source is limited by a 45-min max timer.
Click to expand...
Click to collapse
If you connect the nook to a low power pc port you will only be able to run the charging for 45 minutes before the charger IC stops. To start it again you have to unplug and re-plug the USB cable. The charge current for a 500ma usb port is about 440ma.
The device initiates and completes a charging cycle without software control. It automatically detects the battery
voltage and charges the battery in three phases: pre-conditioning, constant current and constant voltage. At the
end of the charging cycle, the charger automatically terminates when the charge current is below a preset limit in
the constant voltage phase. When the full battery falls below the recharge threshold, the charger will
automatically start another charging cycle.
Click to expand...
Click to collapse
The device fast charges at 1.5A using the charger and charges at 4.208V to the battery. The bad battery setting is for 1.8V, so if your device battery falls to that level it will not charge because the chip assumes a failed battery. I see this a lot in tablets. Someone stops using the tablet when the charge is 10% or less and then 2 weeks later picks up the tablet and it appears dead. The battery cells have discharged below the limit and now will not charge. The device will consume power even if you power off the device because the charging controller is on 24/7 regardless of any mode except shipping mode which we do not have access to . Fix for dead battery is remove the battery from the tablet, charge on external charger , replace.
The USB ports on personal computers are convenient charging source for portable devices (PDs). If the portable
device is attached to a USB host, the USB specification requires the portable device to draw limited current
(100mA/500mA in USB 2.0, and 150mA/900mA in USB 3.0). If the portable device is attached to a charging port,
it is allowed to draw up to 1.5A
Click to expand...
Click to collapse
if you want the info on your own charge stats just type dmesg in a shell prompt.
data to look for is like this:
Code:
<7>[224884.880706] bq2419x_is_vbat_in_range: vbat = 4135000
<7>[224884.881378] bq24196 1-006b: bqSetSYSMIN: 3200
<7>[224884.882019] bq24196 1-006b: adj_fast_ichg_lim: 2036, 240, 2036
<6>[224904.594329] android_usb gadget: high speed config #1: android
<7>[224904.594818] bq24196 1-006b: USB_EVENT_ENUMERATED
<6>[224904.595306] android_work: sent uevent USB_STATE=CONFIGURED
<7>[224904.600708] bq24196 1-006b: INTERRUPT 08=6c, 09=0
<7>[224904.600952] bq24196 1-006b: S: Power Good
<7>[224904.601165] bq24196 1-006b: S: CHARGE STATE = 2 (FAST CHARGING)
<7>[224904.601531] bq24196 1-006b: S: VBUS STATE = 1 (USB host)
<7>[224904.601745] bq24196 1-006b: S: Dynamic Power Management enabled

I have had a few close calls with my battery. It does not charge if verygreen's or other app that permits the Nook to host other USB devices is active, and in most cases I had accidentally activated it. Since it then refuses to charge when connected to power, its in greater danger of completely depleting. Easily fixed as long as the unit is still operating, but no obvious clue when that's the problem.

Also, when you put the power plug in real slow at the nook port, even when the battery is not 100%, it will turn green as if full charged and will no longer show that its charging. Possibly, could be initiated in another way I would think.

modelworks said:
If you connect the nook to a low power pc port you will only be able to run the charging for 45 minutes before the charger IC stops. To start it again you have to unplug and re-plug the USB cable. The charge current for a 500ma usb port is about 440ma.
Click to expand...
Click to collapse
Interesting about the "low power" port. But I haven't seen one yet. Nowadays, many USB2 ports provide up to 1000 mA without negotiation. Originally, the USB specification required that devices connect in a low-power mode (100 mA maximum) and communicate their current requirements to the host, which then permits the device to switch into high-power mode. But the USB Battery Charging Specification changed that. In recent years I've tested several PC mainboards, and an Xbox 360, all of them provide around 1000 mA on USB2 ports without negotiation.
But the Nook HD+ won't make use of that and limit itself to the 440 mA you mentioned. Why? Because it uses the two data lines (D+ and D-) of the USB connection to detect dedicated USB chargers. If the data lines are shorted, the Nook assumes it's connected to a dedicated USB charger and it will draw up to 2000 mA (about 1880 mA in my measurements). If the data lines aren't shorted, it'll limit to 440 mA no matter if the USB power source could provide more.
modelworks said:
The device fast charges at 1.5A using the charger and charges at 4.208V to the battery.
Click to expand...
Click to collapse
From where do you get the 1.5 A? Your own dmesg output says "adj_fast_ichg_lim: 2036, 240, 2036", and as I said, mine charges with around 1.8 A.
Also, the line in the dmesg output that gives away the charging speed isn't "CHARGE STATE". It always reads "= 2 (FAST CHARGING)" when an external power source is connected.
The line "DCP detected" is the real confirmation (DCP = dedicated charging port), and apparently also "VBUS STATE".
"VBUS STATE = 1 (USB host)" means the data lines are NOT shorted => max. current intake is 440 mA
"VBUS STATE = 2 (Adapter port)" means the data lines ARE shorted => max current intake is ~2 A.
Furthermore, keep in mind that power from the external source is prioritized to first supply the system, and then the battery. That is, the battery is charged with the "leftovers". Therefore, if you connect the Nook to a source from which it'll only draw the mentioned 440 mA, and you're continuing to use the tablet, then it can happen that the battery won't be charged, or even will be discharged! If you perform some CPU/GPU intensive tasks on the tablet, its power consumption can easily exceed 440 mA, meaning the tablet will use the external source in combination with the battery to satisfy its hunger.
TL;DR:
Nooks will only fast charge on dedicated charging ports, which are recognized by having their data pins shorted. That's more or less standard nowadays for generic USB chargers (USB Battery Charging Specification). However, some chargers still don't meet this requirement, and Apple has their own incompatible standard, naturally.
Don't use your tablet if you want to charge it from a low-power source (i.e. USB data connection on the Nook), because depending on the workload, the battery will be charged very slowly or will actually be discharged.

Tzul said:
Interesting about the "low power" port. But I haven't seen one yet.
Nowadays, many USB2 ports provide up to 1000 mA without negotiation. Originally, the USB specification required that devices connect in a low-power mode (100 mA maximum) and communicate their current requirements to the host, which then permits the device to switch into high-power mode. But the USB Battery Charging Specification changed that. In recent years I've tested several PC mainboards, and an Xbox 360, all of them provide around 1000 mA on USB2 ports without negotiation.
Click to expand...
Click to collapse
Read page 19 of the document.
From where do you get the 1.5 A? Your own dmesg output says "adj_fast_ichg_lim: 2036, 240, 2036", and as I said, mine charges with around 1.8 A.
Click to expand...
Click to collapse
I just posted that for people to know the general section not as a specific example.
Page 28 of the document explains why the log may read 2036 but actually be 1.5A

modelworks said:
Read page 19 of the document.
Click to expand...
Click to collapse
Have you read it? It's talking about the USB standard there rather than the bq24196. "If the portable device is attached to a charging port, it is allowed to draw up to 1.5A". That's straight from the USB standard, as the common USB2 connectors are rated for up to 1.5 A. However, B&N have engineered their own proprietary cable and connector and provide a 2 A capable power supply, so that limit doesn't apply.
Also, see Table 2 on the same page. The automatic input current limits are 100 mA, 500 mA, and 3 A. Not 1.5 A.
modelworks said:
I just posted that for people to know the general section not as a specific example.
Page 28 of the document explains why the log may read 2036 but actually be 1.5A
Click to expand...
Click to collapse
It would be interesting to open a Nook and take a look what resistor value they used for that safety setting, if they used one at all. As I said before, I've measured currents up to 1.88 A on my Nook HD+ from the official charger, so I seriously doubt they hardwired it to 1.5 A max (and wasted money by providing a 2 A power supply when a 1.5 A one would suffice).
PS: Do you know the power supply dir in the Linux SysFS? Check out /sys/class/power_supply/ and its subfolders (one for each power source). There you can find various virtual files, part of which contain monitoring values straight from the hardware, as read by the driver.
In /sys/class/power_supply/bq27500-0/current_now (or in the file "uevent" which contains a summary of the individual values) you can read the battery charge/discharge current, as measured by the PMU chip. I saw values above 1.7 A there last time I charged and checked. And in order to check, I had to wake up the tablet from standby, of course, meaning that some of the power was spent on running the system rather than charging the battery... All of this paints a pretty clear picture: the device really does fast charge at about 2 A (if you use a suitable power supply and if you let the tablet sleep while charging). Not 1.5 A.

modelworks said:
The device fast charges at 1.5A using the charger and charges at 4.208V to the battery. The bad battery setting is for 1.8V, so if your device battery falls to that level it will not charge because the chip assumes a failed battery. I see this a lot in tablets. Someone stops using the tablet when the charge is 10% or less and then 2 weeks later picks up the tablet and it appears dead. The battery cells have discharged below the limit and now will not charge. The device will consume power even if you power off the device because the charging controller is on 24/7 regardless of any mode except shipping mode which we do not have access to . Fix for dead battery is remove the battery from the tablet, charge on external charger , replace.
Click to expand...
Click to collapse
Just wondering how do you charge the battery externally?

invinciblemo said:
Just wondering how do you charge the battery externally?
Click to expand...
Click to collapse
By opening the tablet, removing the battery, and connecting it to a dedicated Li-ion charger, of course. Something like this - but that's just an example, that model would not work. You'd probably have to do some soldering for the connector, too.

Tzul said:
By opening the tablet, removing the battery, and connecting it to a dedicated Li-ion charger, of course. Something like this - but that's just an example, that model would not work. You'd probably have to do some soldering for the connector, too.
Click to expand...
Click to collapse
I tried finding online to see if anyone had tried charging the battery externally.
It seems that dormouse1, from the second post in this thread http://4pda.to/forum/index.php?showtopic=431820&st=1900, had tried charging it using Imax B6.
I'm going to try charging my battery using his setup and see if it works.

To anyone that is interested in charging their battery externally, i think a TP4056 a Lipo Battery Charging Board works.
I had managed to charge my battery, and it shows that it has a discharge voltage of 4V, but I am not sure if it is correct.
When my charged battery is connected to my tablet, the battery discharged and my tablet became hotter.
However, my tablet failed to boot.
So its either that my tablet is bricked, or the charger did not charge my battery properly.
I would like to ask does anyone knows, what is the voltage of a fully charged battery?

invinciblemo said:
I would like to ask does anyone knows, what is the voltage of a fully charged battery?
Click to expand...
Click to collapse
Lithium-ion cells are typically charged to 4.20V. The Nook HD+ uses that value, too. Nominal voltage is 3.7V. I forgot the cut-off voltage that the HD+ uses to decide that the battery is empty, but I think it was 3.4V or 3.5V.

Tzul said:
Lithium-ion cells are typically charged to 4.20V. The Nook HD+ uses that value, too. Nominal voltage is 3.7V. I forgot the cut-off voltage that the HD+ uses to decide that the battery is empty, but I think it was 3.4V or 3.5V.
Click to expand...
Click to collapse
To add to that, make sure you put a load on the battery if you are measuring the voltage of the battery disconnected.
Something like a single 330 ohm resistor would be good.
Bad lithium batteries sometimes will appear charged until you place the load on it then it falls to 2 or lower volts.
Another quick check is to make sure the battery casing is completely flat, if the battery has bulges of more than a few millimeters the battery is about to fail and should be discarded immediately. Another trick you can use is smell the battery, I know sounds weird , but failing lithium batteries have a very unique odor , almost sweet, reminds me of the smell of bananas.

HTML:
Tzul said:
[*]Nooks will only fast charge on dedicated charging ports, which are recognized by having their data pins shorted. That's more or less standard nowadays for generic USB chargers (USB Battery Charging Specification). However, some chargers still don't meet this requirement, and Apple has their own incompatible standard, naturally.
[*]Don't use your tablet if you want to charge it from a low-power source (i.e. USB data connection on the Nook), because depending on the workload, the battery will be charged very slowly or will actually be discharged.
Click to expand...
Click to collapse
I have an HD+, which I have not been able to get to charge on a 3amp, 2amp or even a 1amp wallwart, but it does charge via its Nook wallwart. Does the above mean that were I to 'repurpose' a short USB extension and simply short the D- and D+ (clear of the +ve and ground) together in the USB lead, that I should then find it will charge via that lead? Please?

harrym1byt said:
Does the above mean that were I to 'repurpose' a short USB extension and simply short the D- and D+ (clear of the +ve and ground) together in the USB lead, that I should then find it will charge via that lead? Please?
Click to expand...
Click to collapse
Sorry for the late response.
Yes, that is correct, I have built such a cable myself and it does work.

Battery Issues
I have a Nook HD and it immediately dies as soon as it is unplugged, however there is no apparent damage to the battery, no bulges, leaks, or smells. After I plug it in and it reboots it goes from 10-20% charge to 100% charge within minutes. Is there a way other than removing the battery and charging it externally (outiside of my mechanical ability) to reset the battery to determine if it is a software issue or an issue with the battery itself. Currently running CM 10.2.1 stable.

Charging problem - solved
I had similar symptoms with my Nook HD+ : when plugged into charger the indicator light turned green, then orange, but only for a second, then went dark. When left on charger for many hours, the indicator would start blinking red. Nothing worked, until I read technical details in this thread.
The bottom line: if the battery voltage drops below 1.8 V, the stupid control chip assumes the battery is "bad" and refuses to pass the charging current; consistent with the observed symptoms. This gave me an idea on how to fix this:
Step 1: Open the Nook by prying the front panel to get access to mounting screws, then unscrew the back panel.
Step 2: Locate the battery cable composed of three red, three black, one blue, and one yellow wires.
Step 3: Locate the gold test points on circuit board _under_ the wires: "VBAT" under the red wires, "BAT-" under the black wires.
Step 4: You have to trick the control chip into "thinking" that the battery is still "good". For this, you'll need an external voltage source. I used my homemade adjustable DC power supply setting it to 2.5 V. I guess, any voltage between 1.8 - 3.7 should work.
Step 5: Connect the _positive_ lead from the external power source to the "VBAT" test point, connect _negative_ (or ground) lead to the "BAT-" test point.
Step 6: Plug your Nook into charger and wait a few seconds: the indicator light will now stay solid orange meaning the charging current is passing through. Yay! You should disconnect the external DC source; it's no longer needed.

I can confirm that applying voltage to the test points does absolutely nothing. In examining the PCB the test points mirror the positive and negative connections of payload from the battery.
That is NOT how the charging chip works. There are 2 control lines tied internally to the LiPo battery which are NOT payload lines. That is what we need to play with but there's no information on how those control lines are tied into the cell's internal chemistry or what the expected levels might be for the chip to "think" that the battery is good. It could even be an interface, i2c or who knows

I guess I am in trouble then...
I found my Nook HD+ back after not having used it in 3 years. Battery is dead as a door nail. When I plugged it in though, it showed the battery symbol for a dead battery and then the amber light next to the cable connector lit up and is still lit 30 minutes later. I am going to let it charge overnight and hope that it works again. If not, I don't think I will bother with pulling the battery, etc.

Dash Charge protocol analysis

On the Oneplus forum there is a thread where they analysed the dash-charging cable ( https://forums.oneplus.net/threads/...-cable-doing-internally-lets-probe-it.456017/ ).
The topic was finished by somebody posting a teardown of the cable revealing that it's dash-charging capabilities are encoded on a BQ2022 from ti.
The next logical step is to dig into the communication between the phone and the charger.
The same guy that tore down the cable also took a look at the chargers (google translate will be helpfull):
http://www.chongdiantou.com/wp/archives/1228.html Mains
http://www.chongdiantou.com/wp/archives/1339.html Car
Maybe we can continue the investigation here....

So, I did some digging around the Car-Unit with my Logic Analyzer.
Description of setup here: http://imgur.com/a/G7pPN
The charger waits for a current draw (i didn't bother testing it's thresholds) and then reads/checks-for the E²PROM embedded in the plug of the cable (presumably containing an authentication for dash).
At a similar time the phone sends a kind of "preamble" consisting of high-low transitions of varying lengths (but this doesn't seem to important to the charger, it tries to "dash" even without it).
Afterwards the phone and charger start exchanging 9 bits of data in bursts. One USB-Data-Line is clock, the other one is data. The chargers supplies the clock and the first 9 bits and after a short pause the phone gets to reply with another 9 bits as the charger supplies another "clock-burst".
At the beginning (before dash-charging is in effect), the charger sends 150h and the phone replys with 158h.
Once the phone is ready to begin dash-charging it replys with 178h instead.
The charger then configures it's Step-Down Converter for ~4.5V of output voltage and then sends 148h to the phone.
It either replies with 170h if the voltage is too high or 178h if the voltage is correct (I didn't see a reply for "too low", but it might exist).
If the phone replies 170h the charger lowers the voltage by about 100mV-200mV and "asks" again.
Once the phone replies with 178h the charger stops lowering the voltage and sends 14Ch to which the phone replies with 141h.
During the dash-charging process the charger periodically sends 144h to which the phone replies with a number which seems to roughly coincide with the state of charge (i have seen values from 16Eh to 178h).
The charger seems to nudge-up the voltage every once in a while (presumably when the current dropped below a threshold).
If the battery is relatively full (i tested at 90% charge) the "dash-charging-cycle" doesn't even start and the communication stays at an exchange of 150h/158h data "words".
I did some minor probing on the wall-wart with a stripped USB 3.0 extension and found that it uses the same commands but with the lowest bit set (i.e. it adds 1 to the command codes). Unfortunately the USB 3.0 cable had some internal resistance ruining most of the analog measurements.
todo:
- I didn't manage to capture is the transition from dash charging back to "normal" 5V mode at the end of the charge cycle.
- The values communicated at the transition from the voltage-setting process to the dash charging operation are unclear to me (but they appear to be always the same).

Do you think it's safe to use OnePlus 3 brick or car Dash charger with let's say micro USB cable and charge other phones? Or OnePlus power bank?

nitramcek said:
Do you think it's safe to use OnePlus 3 brick or car Dash charger with let's say micro USB cable and charge other phones? Or OnePlus power bank?
Click to expand...
Click to collapse
it's safe as with other phone or cable it will act as a normal charger blocking at 1.5A.
Dash charge will only activate if, the dash cable is used with a dash charging phone or oppo vooc phone.

Le_Zouave said:
it's safe as with other phone or cable it will act as a normal charger blocking at 1.5A.
Dash charge will only activate if, the dash cable is used with a dash charging phone or oppo vooc phone.
Click to expand...
Click to collapse
Great, so It's safe to use my car Dash charger for charging other phones to.

atheist93 said:
So, I did some digging around the Car-Unit with my Logic Analyzer.
Description of setup here: http://imgur.com/a/G7pPN
The charger waits for a current draw (i didn't bother testing it's thresholds) and then reads/checks-for the E²PROM embedded in the plug of the cable (presumably containing an authentication for dash).
At a similar time the phone sends a kind of "preamble" consisting of high-low transitions of varying lengths (but this doesn't seem to important to the charger, it tries to "dash" even without it).
Afterwards the phone and charger start exchanging 9 bits of data in bursts. One USB-Data-Line is clock, the other one is data. The chargers supplies the clock and the first 9 bits and after a short pause the phone gets to reply with another 9 bits as the charger supplies another "clock-burst".
At the beginning (before dash-charging is in effect), the charger sends 150h and the phone replys with 158h.
Once the phone is ready to begin dash-charging it replys with 178h instead.
The charger then configures it's Step-Down Converter for ~4.5V of output voltage and then sends 148h to the phone.
It either replies with 170h if the voltage is too high or 178h if the voltage is correct (I didn't see a reply for "too low", but it might exist).
If the phone replies 170h the charger lowers the voltage by about 100mV-200mV and "asks" again.
Once the phone replies with 178h the charger stops lowering the voltage and sends 14Ch to which the phone replies with 141h.
During the dash-charging process the charger periodically sends 144h to which the phone replies with a number which seems to roughly coincide with the state of charge (i have seen values from 16Eh to 178h).
The charger seems to nudge-up the voltage every once in a while (presumably when the current dropped below a threshold).
If the battery is relatively full (i tested at 90% charge) the "dash-charging-cycle" doesn't even start and the communication stays at an exchange of 150h/158h data "words".
I did some minor probing on the wall-wart with a stripped USB 3.0 extension and found that it uses the same commands but with the lowest bit set (i.e. it adds 1 to the command codes). Unfortunately the USB 3.0 cable had some internal resistance ruining most of the analog measurements.
todo:
- I didn't manage to capture is the transition from dash charging back to "normal" 5V mode at the end of the charge cycle.
- The values communicated at the transition from the voltage-setting process to the dash charging operation are unclear to me (but they appear to be always the same).
Click to expand...
Click to collapse
Really interesting analysis. What's your goal? Enabling dash charging without dash accessories?
(USB-C for example)

My primary motivation is curiosity.
If the protocol turns out to be sufficiently simple to replicate (which is looking good at the moment) I might try and build a dash powerbank to quickly top of my battery. I wouldn't want 3+ Amps going through a flimsy micro-to-c adapter from a vooc bank...

atheist93 said:
My primary motivation is curiosity.
If the protocol turns out to be sufficiently simple to replicate (which is looking good at the moment) I might try and build a dash powerbank to quickly top of my battery. I wouldn't want 3+ Amps going through a flimsy micro-to-c adapter from a vooc bank...
Click to expand...
Click to collapse
hmm, so you're trying to replicate it on the hardware side, that's a cool application and it'd be great to have other options for power banks and car chargers.
i honestly don't know much about the topic, but do you think i'd be possible to replicate it on the software side? ie, mimic the protocol to enable faster charging when plugged into a USB-C fast charging output? (but also limit it to 3A since that's a safe max similar to the Nexus 5X/6P)

I am pretty sure that it is not possible to do it in software only.
The whole point of Dash is to let the charger do the regulating and make the phone just "pass-through" the raw connection to the battery.
You might be able to trick the phone into switching it's "pass-through" feature on without getting the right initialization, but this would frankly be stupid as the result would be 5V from the USB-Port pushing directly into the lithium cell which is supposed to stay below 4,2V. Initially the internal resistance of the USB-Cable might limit the current sufficiently to prevent an immediate catastrophic failure, but I can't imagine it working out well in the long run...
The only possible solution i see for this to work is to have a device that plugs into your existing USB and steps down the voltage appropriately, but that is hardware again.

atheist93 said:
I am pretty sure that it is not possible to do it in software only.
The whole point of Dash is to let the charger do the regulating and make the phone just "pass-through" the raw connection to the battery.
You might be able to trick the phone into switching it's "pass-through" feature on without getting the right initialization, but this would frankly be stupid as the result would be 5V from the USB-Port pushing directly into the lithium cell which is supposed to stay below 4,2V. Initially the internal resistance of the USB-Cable might limit the current sufficiently to prevent an immediate catastrophic failure, but I can't imagine it working out well in the long run...
The only possible solution i see for this to work is to have a device that plugs into your existing USB and steps down the voltage appropriately, but that is hardware again.
Click to expand...
Click to collapse
a physical device which enables dash charging, particularly up to 3A via USB-C and 2.4A via USB-A to USB-C, would be of great use too

atheist93 said:
My primary motivation is curiosity.
If the protocol turns out to be sufficiently simple to replicate (which is looking good at the moment) I might try and build a dash powerbank to quickly top of my battery. I wouldn't want 3+ Amps going through a flimsy micro-to-c adapter from a vooc bank...
Click to expand...
Click to collapse
I bought the Dash car charger to be used as a car charger as well as backup power for camping etc. The dash charger seems to work with a wide range of input voltage. I would guess 8V-28V works fine.
I tested the dash car charger with eight AA Eneloop batteries but it didn't work well. The input voltage dropped from 11V to 6,6V. I think the stress was too much for eight batteries and dash charging didn't work. Ampere (app) displayed a reading of 1120mA for charging current.
Ten AA Eneloops were enough to dash charge the phone twice from 40% -> 90%. I also tested the dash car charger with a 19V PSU and it workerd fine as well.
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The next step is to buy lifepo 4 / lipo battery and build a case.

Thanks for the work done.
The problems with the enelope is the wiring... I guess there will be a massive voltage drop over the holder/wires and clips.
These things are not made for higher currents. I have seen experiments failing because of battery holders and crocodile clips very often. The problem is that these cables often have massive resistance which is no problem as long there is no current flowing... Greetings from Ohms law

Squabl said:
I bought the Dash car charger to be used as a car charger as well as backup power for camping etc. The dash charger seems to work with a wide range of input voltage. I would guess 8V-28V works fine.
I tested the dash car charger with eight AA Eneloop batteries but it didn't work well. The input voltage dropped from 11V to 6,6V. I think the stress was too much for eight batteries and dash charging didn't work. Ampere (app) displayed a reading of 1120mA for charging current.
Ten AA Eneloops were enough to dash charge the phone twice from 40% -> 90%. I also tested the dash car charger with a 19V PSU and it workerd fine as well.
The next step is to buy lifepo 4 / lipo battery and build a case.
Click to expand...
Click to collapse
How did your project go? And why Lipo batteries? Why not 18650 batts?

MonoTovarisj said:
How did your project go? And why Lipo batteries? Why not 18650 batts?
Click to expand...
Click to collapse
You can get custom Li-Po batteries to fit any size and are generally square. 18650s are cylindrical and there would be wasted space between the batteries so with a Li-Po you would be able to get higher capacity. Just a wild guess

MonoTovarisj said:
How did your project go? And why Lipo batteries? Why not 18650 batts?
Click to expand...
Click to collapse
I ended up using battery from my 18V cordless drill. The battery is quite small and light weight for it capacity. It was the easiest and cheapest option as I need battery backup very seldom.

I did a case for 4 x 18650 and the car charger, but got a little stuck in the project. Mostly because I don't have any electronic skills.

This looks cool.
What questions do you have? I can help out with the electronics. But it seems to be quite straight forward. But to be safe use protected 18650 cells. I can recommend the Panasonic NCR18650b, they are the best ones currently available. See: https://www.gearbest.com/batteries/pp_187046.html. You might need to adjust your design the protection makes them a bit longer than standart 18650 cells.

The design is already for the panasonic protected 18650 cells. However I would have liked a pcb in the buttom with full charging circuit and a usb-c for charging. With my current design I have to take the cells out for charging. :-/

MonoTovarisj said:
The design is already for the panasonic protected 18650 cells. However I would have liked a pcb in the buttom with full charging circuit and a usb-c for charging. With my current design I have to take the cells out for charging. :-/
Click to expand...
Click to collapse
You want to connect the 4 cells in series right?
I haven't found any good 4s charging modules yet.
Building you own charger circuit based on an charger IC is hardcore electronics. I have tried and i took months.
So charging the externally should be fine really.

affmalg said:
You want to connect the 4 cells in series right?
I haven't found any good 4s charging modules yet.
Building your own charger circuit based on a charger IC is hardcore electronics. I have tried and I took months.
So charging the externally should be fine really.
Click to expand...
Click to collapse
Yeah series, as I need the voltage for the car charger, and 3.7 times 4 gives a nice 14,8V for the charger.
Regarding charging that was my conclusion as well, however if I wanted to commercialise it, I would need a built-in charging circuit.
I would be able to get wires to the top poles as well if that would help the design, then you would be able to charge them individually and switch to a serial connection when in use.

Galaxy tab s2 9.7 very Slow charging!

Hi.
My galaxy tab s2 charging very slowly. It takes about 3 days to full charge.
I allready try 15 or more chargers and cabels (including original).
I format and delete cache files
I downgrade to android 6.0.1
I replace the charging port
The only thing i don't do is to replace the battery, but the battery (when finally get charged) drain like normal.
Please help i really dont have anymore ideas.
Thank you!

I have this also. Had slow charging for months. The first time samsung fixed it and sent me a new charger. The second time i was out of warranty so i replaced the charging port myself, tried many different chargers and cables and can't figure it out. It charges really really slow.

leyvatron said:
I have this also. Had slow charging for months. The first time samsung fixed it and sent me a new charger. The second time i was out of warranty so i replaced the charging port myself, tried many different chargers and cables and can't figure it out. It charges really really slow.
Click to expand...
Click to collapse
I charge with my Moto fast charger and it seems to charge it faster than the Samsung one.

jahciple said:
I charge with my Moto fast charger and it seems to charge it faster than the Samsung one.
Click to expand...
Click to collapse
if you have slow charging issue, the tablet gives you a warning to use the original charger to charge it fast. If you don't get the notification of slow charging, then your tablet doesn't have any charging issues.

update: i replaced the charging port and the battery. but still no luck. the percentages keep dropping when my fast charger is connected
i'm out of ideas so if someone have some thoughts i'm listening.

Itamar1239 said:
update: i replaced the charging port and the battery. but still no luck. the percentages keep dropping when my fast charger is connected
i'm out of ideas so if someone have some thoughts i'm listening.
Click to expand...
Click to collapse
I wanted to call Samsung and asked them what they fixed when I sent it to them when it was on warranty.

leyvatron said:
I wanted to call Samsung and asked them what they fixed when I sent it to them when it was on warranty.
Click to expand...
Click to collapse
now the battery stops charging at 22% (it takes 1 day to charge to 22% lol)
if you call samsung please let me know what they said.
thank you.

Itamar1239 said:
now the battery stops charging at 22% (it takes 1 day to charge to 22% lol)
if you call samsung please let me know what they said.
thank you.
Click to expand...
Click to collapse
did you disconnect and reconnect the battery?

leyvatron said:
did you disconnect and reconnect the battery?
Click to expand...
Click to collapse
I did.
And like i said i even replace the battery
But still no luck.
I suspect that some chip on the motherboard is not working right, but that just guessing.
Any more ideas are more than welcome

Itamar1239 said:
I did.
And like i said i even replace the battery
But still no luck.
I suspect that some chip on the motherboard is not working right, but that just guessing.
Any more ideas are more than welcome
Click to expand...
Click to collapse
Also out of ideas myself

As I wrote on samsungboard recently;
"I have tried multiple cables*(that work fine with all other phones - Samsung S7/Galaxy tab S2 9.7/Sony etc)
I have tried multiple chargers (Samsung quick charge as well as Samsung standard and Anker 6 port charger)
Tried changing the USB mode (*#0808#)
I have tried resetting device (long press vol up/down/power)
When connecting device to PC to use Odin to downgrade it is not even seen by Windows 10 (again it only charges albeit slowly - this to me is an indication that D+/D- are not handled correctly by the PMIC sw which in my mind is the root cause of this whole issue).
"
https:// us. community.samsung.com/t5/forums/v3_1/forumtopicpage/board-id/tablets/thread-id/1961/page/5
I also see in devops bugreport-xxxx.txt cable type is 4 and wire_status 4;
<6>[16050.764777] [c1] sec-battery battery.27: sec_bat_set_property: current_cable(4), wc_status(0), wire_status(4)
<6>[16050.764884] [c0] sec-battery battery.27: sec_bat_cable_work: Start
<6>[16050.764904] [c0] sec-battery battery.27: sec_bat_cable_work: Cable is NOT Changed(4)
<6>[16050.767168] [c1] sii8240: detection restarted
<6>[16050.767187] [c1] of_sii8240_hw_reset()
<6>[16050.769768] [c1] sec_chg_get_property: slow-charging mode
Whereas in kernel/kmsg logs cable type is 1;
<6>[ 4.613200] [c6] sec_chg_get_property: Charger Cable type : 1
Skickat från min BLA-L29 via Tapatalk

luckeb said:
As I wrote on samsungboard recently;
"I have tried multiple cables*(that work fine with all other phones - Samsung S7/Galaxy tab S2 9.7/Sony etc)
I have tried multiple chargers (Samsung quick charge as well as Samsung standard and Anker 6 port charger)
Tried changing the USB mode (*#0808#)
I have tried resetting device (long press vol up/down/power)
When connecting device to PC to use Odin to downgrade it is not even seen by Windows 10 (again it only charges albeit slowly - this to me is an indication that D+/D- are not handled correctly by the PMIC sw which in my mind is the root cause of this whole issue).
"
https:// us. community.samsung.com/t5/forums/v3_1/forumtopicpage/board-id/tablets/thread-id/1961/page/5
I also see in devops bugreport-xxxx.txt cable type is 4 and wire_status 4;
<6>[16050.764777] [c1] sec-battery battery.27: sec_bat_set_property: current_cable(4), wc_status(0), wire_status(4)
<6>[16050.764884] [c0] sec-battery battery.27: sec_bat_cable_work: Start
<6>[16050.764904] [c0] sec-battery battery.27: sec_bat_cable_work: Cable is NOT Changed(4)
<6>[16050.767168] [c1] sii8240: detection restarted
<6>[16050.767187] [c1] of_sii8240_hw_reset()
<6>[16050.769768] [c1] sec_chg_get_property: slow-charging mode
Whereas in kernel/kmsg logs cable type is 1;
<6>[ 4.613200] [c6] sec_chg_get_property: Charger Cable type : 1
Skickat från min BLA-L29 via Tapatalk
Click to expand...
Click to collapse
thank for the info.
Like I said, I sent in my tablet to Samsung when it was under warranty with the original white samsung charger and they sent the tablet back with a slower charging black samsung charger. I have exchange the usb port, tried different cables and plugs, tried resetting, etc... and nothing has worked.
Keep us updated on what happens. :good:

leyvatron said:
thank for the info.
Like I said, I sent in my tablet to Samsung when it was under warranty with the original white samsung charger and they sent the tablet back with a slower charging black samsung charger. I have exchange the usb port, tried different cables and plugs, tried resetting, etc... and nothing has worked.
Keep us updated on what happens. :good:
Click to expand...
Click to collapse
Hi, Charging cable from Cambridge Soundworks Oontz angle 2 has worked for me.

hi Guys!!!!!!!! i too had the same problem stated above and i got the reason of it in youtube and here is the link of the video:
and this video tells that we need to replace the IC of the device where this problem is very common in most of samsung galaxy tab s2's

vjackaadhitya said:
hi Guys!!!!!!!! i too had the same problem stated above and i got the reason of it in youtube and here is the link of the video:
and this video tells that we need to replace the QC of the device where this problem is very common in most of samsung galaxy tab s2's
Click to expand...
Click to collapse
That's not something most people can do... successfully. These are the hardest type of ICs to replace. A precision temp controlled hot air station with the skillset to use it is required. Full ESD protocols need to followed. You can easily destroy the multilayered PCB if you don't do it right... you get one shot at it.

I have T715Y, and it's really slow to charge. The current monitor show that it only pull 0.45A. The charger itself capable of supplying more than 2A on other device.
On the tablet, I try to monitor the current internally, and it said it connect to usb powered, not ac powered, and I already tried swapping other chargers. Maybe that's why it's only pulling half amps. Tried cleaning the charging port with some isoprophil alcohol and pinset, nothing change. Maybe I need to swap the charging port, but searching it in 2021 was hard.
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@xdanubi it shouldn't use AC as batteries are only being charged by DC.

xdanubi said:
I have T715Y, and it's really slow to charge. The current monitor show that it only pull 0.45A. The charger itself capable of supplying more than 2A on other device.
On the tablet, I try to monitor the current internally, and it said it connect to usb powered, not ac powered, and I already tried swapping other chargers. Maybe that's why it's only pulling half amps. Tried cleaning the charging port with some isoprophil alcohol and pinset, nothing change. Maybe I need to swap the charging port, but searching it in 2021 was hard.
View attachment 5389291
Click to expand...
Click to collapse
If the device is in use it will likely skew the charging curve and not draw as much as with the screen off. If you turn the display on and read within a second or less while charging you can probably see what it's actually drawing screen off.
Or simply count how many seconds it takes to charge 1% or minutes to charge to 10%, etc.
If the battery capacity has dropped more than 80% of it's original capacity it's time to replace it before it fails.
Any battery swelling is a failure, replace asap.
Erratic charging can indicate a failure as well.
A sudden drop in capacity indicates a failure.
It could simply be a failed battery.
A battery will last roughly 1-3 years depending how it's used/conditions ie temperature and time it's at near 100%.

My S2 started exhibiting this problem too. Basically it won't pull more than 450 ma from the charger. I discovered that with a custom charge cable that shorts the usb lines together, I was able to get it to draw about 1.5 amps @ 5v. You can get a little more if you supply it with a little more volts (5.5 for instance).
Currently i am using a bench power suppy connected to a micro usb tail that has the dp dm lines tied together.
I have some usb c female breakouts coming from amazon today that I will solder on to my custom micro usb tail which will hopefully allow me to charge it from my 6 port vogek charger.
I agree that it most likely had an IC go bad but replacing that is a MAJOR under taking. 1.5 amps is enough that it will still get about 1 amp charge while your actively using it so theoretically it should go from 0 to 100% in 5.8 hours. Less if you power it down. Good enough!

trnexus01234 said:
My S2 started exhibiting this problem too. Basically it won't pull more than 450 ma from the charger. I discovered that with a custom charge cable that shorts the usb lines together, I was able to get it to draw about 1.5 amps @ 5v. You can get a little more if you supply it with a little more volts (5.5 for instance).
Currently i am using a bench power suppy connected to a micro usb tail that has the dp dm lines tied together.
I have some usb c female breakouts coming from amazon today that I will solder on to my custom micro usb tail which will hopefully allow me to charge it from my 6 port vogek charger.
I agree that it most likely had an IC go bad but replacing that is a MAJOR under taking. 1.5 amps is enough that it will still get about 1 amp charge while your actively using it so theoretically it should go from 0 to 100% in 5.8 hours. Less if you power it down. Good enough!
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What is your experience so far? Does your custom cable work? If yes can you please be more specific how to construct it? There are many users with the same problem!