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This is a stock kernel for GSM Galaxy Nexus 4.0.3 with the following properties:
Root access with adb (a.k.a. insecure)
Charger is modified to stop charging at 4000mV and > 80%, and start charging again at 3990mV or < 80%.
Rationales:
Stock kernel: I value compatibility and stability. While the various mods and new features are undoubtedly very useful for many people, some of them are not well tested which results in lower stability. That is not to say stock Android is extremely stable (it is not), adding new features on top of which very often increases the likelyhood of crashes.
Limited charging: As a developer, my phone is virtually plugged in the computer all the time. As many of you are aware, leaving the phone charged greatly reduces battery life (Ref). This kernel frees you from having to unplugging and plugging in the phone repeatedly in fear of destroying your precious battery.
Visible differences:
Charging percentage will not increase after the phone is charged to 80% or more.
The phone never reports full charge, even if it's charged while being turned off. That means battery stats can accumulate which, after a while, makes it practically useless as the diagram is too compressed. This is a plus to me as I can see how I manage the battery over time, although I can make an alternate version which reports full charge whenever the phone stops charging under requests.
Perhaps I'm the only one who is paranoid about keeping battery charge between 10-90%, I wouldn't be surprised if no one is interested it this at all.
The kernel can be flashed using Odin or fastboot. If someone wants a CWM-flashable zip let me know.
Cheers.
You could have simply used my BLX mod.
Ezekeel said:
You could have simply used my BLX mod.
Click to expand...
Click to collapse
Glad to know I'm not the only one. When I was using the SGS2 I spent quite a bit of time looking for such mod to no avail. Searching for "android|galaxy nexus limit charging voltage" turned up lots of posts about changing kernel voltage which wasn't what I wanted.
I like to keep the kernel close to stock, but thanks anyway .
Hey, an idea to you devs: what about a apk that schedules the charge limit? for example, if you use to charge your phone at night and you wake up at 7 that app could charge the phone @ 60% and at 6 start charging'till it reaches the 100%
With ezekeel BLX mod it should be easy to schedule modifying the file, but i have no idea on programming nor cron
Guzmanus said:
Hey, an idea to you devs: what about a apk that schedules the charge limit? for example, if you use to charge your phone at night and you wake up at 7 that app could charge the phone @ 60% and at 6 start charging'till it reaches the 100%
With ezekeel BLX mod it should be easy to schedule modifying the file, but i have no idea on programming nor cron
Click to expand...
Click to collapse
You can do that with Tasker, it is a bit on the heavy side but saves having another service running in the background while leaves the possibility to do a lot more. I'm not aware of other light-weight but user friendly solutions for managing scripts, perhaps others could chime in.
Ezekeel said:
You could have simply used my BLX mod.
Click to expand...
Click to collapse
agree with ezekieel...his Battery Life eXtender (BLX)do the same thing(via file /sys/class/misc/batterylifeextender/charging_limit default 100),without give up at all the tweaks,oc,color control etc. try that if you want.anyway thanks for the work,personally it not interest me,but certainly someone will find it usefull!
fnf said:
This is a stock kernel for GSM Galaxy Nexus 4.0.3 with the following properties:
Root access with adb (a.k.a. insecure)
Charger is modified to stop charging at 4000mAh and > 80%, and start charging again at 3990mAh or < 80%.
Rationales:
Stock kernel: I value compatibility and stability. While the various mods and new features are undoubtedly very useful for many people, some of them are not well tested which results in lower stability. That is not to say stock Android is extremely stable (it is not), adding new features on top of which very often increases the likelyhood of crashes.
Limited charging: As a developer, my phone is virtually plugged in the computer all the time. As many of you are aware, leaving the phone charged greatly reduces battery life (Ref). This kernel frees you from having to unplugging and plugging in the phone repeatedly in fear of destroying your precious battery.
Visible differences:
Charging percentage will not increase after the phone is charged to 80% or more.
The phone never reports full charge, even if it's charged while being turned off. That means battery stats can accumulate which, after a while, makes it practically useless as the diagram is too compressed. This is a plus to me as I can see how I manage the battery over time, although I can make an alternate version which reports full charge whenever the phone stops charging under requests.
Perhaps I'm the only one who is paranoid about keeping battery charge between 10-90%, I wouldn't be surprised if no one is interested it this at all.
The kernel can be flashed using Odin or fastboot. If someone wants a CWM-flashable zip let me know.
Cheers.
Click to expand...
Click to collapse
Source code?? It has to have a link.
Since you modified the kernel
Mikey said:
Source code?? It has to have a link.
Since you modified the kernel
Click to expand...
Click to collapse
Not much to speak of tbh. Here is the patch. You can build it from the stock branch 4.0.3_r1 . I changed the compilation flags so it better matches Cortex A9 but I'm sure there are rooms for performance improvements.
GLaDOS kernel has this value configurable as well so aside from being stable, this kernel is worse all around .
I assume you meant 4000 mV, not 4000 mAh? Considering that not even extended batteries I've seen exceed 3500 mAh?
Entropy512 said:
I assume you meant 4000 mV, not 4000 mAh? Considering that not even extended batteries I've seen exceed 3500 mAh?
Click to expand...
Click to collapse
Post amended, thanks .
fnf said:
This is a stock kernel for GSM Galaxy Nexus 4.0.3 with the following properties:
Root access with adb (a.k.a. insecure)
Charger is modified to stop charging at 4000mV and > 80%, and start charging again at 3990mV or < 80%.
Click to expand...
Click to collapse
Ezekeel said:
You could have simply used my BLX mod.
Click to expand...
Click to collapse
Greetings gentlemen! I've been testing wireless charging with Galaxy Nexus and Nexus 5, and while I like the technology, I'm not comfortable with two side-effects: higher battery temperature, and higher average battery charge voltage. I'd like to work around this by limiting the charge capacity to 80% / 4.0v.
I think the lost battery capacity will work for me because the way I'm using the wireless chargers is keeping the batteries topped up all day. By keeping wireless chargers by the bed and the main work space, the phones hardly ever run down! But this also keeps the battery at 100% constantly. Thus my 5-year-old bright idea to limit the voltage!
What's the state of the art of this problem solution? Should I ask a kernel developer to include https://github.com/Ezekeel/GLaDOS-nexus-s/tree/blx ?
I am playing with Fastcharge in JB with the Faux Kernel. Here are the specifics of my experiment.
App: Galaxy Nexus Fast Charge (from market). I wish there was a toggle or widget but I'll probably have to wait for AOKP JB.
All charges were done with networking OFF, screen OFF. I would have liked to do a longer experiment but I didn't have time and didn't think extending the experiment time would yield a noticeable difference.
The phone did in fact register as an INTF2 device when I turned on fastcharge, where it shows as a Media Device when it's in USB mode. This is the same as when I had it in ICS (AOKP) with Franco Kernel, which definitely worked (very well).
Phone: Galaxy Nexus LTE
Carrier: Verizon
ROM: Vicious Jelly Bean V5
Kernel: Faux Kernel JB 019
Fastcharge OFF, 10 minutes, USB = 5%
Fastcharge ON, 10 minutes, USB = 9%
I wanted to see if it would also change the voltage/amperage draw from the stock charger that came with the phone.
Fastcharge OFF, 10 minutes, AC = 9%
Fastcharge ON, 10 minutes, AC = 9%
AC was same as expected. I didn't know the kernel had fast charge mode since it doesn't brag this feature but apparently it does.
This is good news considering the poor battery life I've gotten with Vicious JB/Faux Kernel compared to the great life with AOKP ICS/Franco Kernel.
look4alec said:
I am playing with Fastcharge in JB with the Faux Kernel. Here are the specifics of my experiment.
App: Galaxy Nexus Fast Charge (from market). I wish there was a toggle or widget but I'll probably have to wait for AOKP JB.
All charges were done with networking OFF, screen OFF. I would have liked to do a longer experiment but I didn't have time and didn't think extending the experiment time would yield a noticeable difference.
The phone did in fact register as an INTF2 device when I turned on fastcharge, where it shows as a Media Device when it's in USB mode. This is the same as when I had it in ICS (AOKP) with Franco Kernel, which definitely worked (very well).
Phone: Galaxy Nexus LTE
Carrier: Verizon
ROM: Vicious Jelly Bean V5
Kernel: Faux Kernel JB 019
Fastcharge OFF, 10 minutes, USB = 5%
Fastcharge ON, 10 minutes, USB = 9%
I wanted to see if it would also change the voltage/amperage draw from the stock charger that came with the phone.
Fastcharge OFF, 10 minutes, AC = 9%
Fastcharge ON, 10 minutes, AC = 9%
AC was same as expected. I didn't know the kernel had fast charge mode since it doesn't brag this feature but apparently it does.
This is good news considering the poor battery life I've gotten with Vicious JB/Faux Kernel compared to the great life with AOKP ICS/Franco Kernel.
Click to expand...
Click to collapse
wrong section
j.curtis.369 said:
wrong section
Click to expand...
Click to collapse
Can a Mod move it please? I never post as you can see. I am not sure where it would belong, as it's more of a Kernel review than anything.
Nexus noob here. What is fastcharge? Does it basically remove any USB connection options and increase the charging speed?
Those guys did compile a GSM version I found it fishing around inside Goo and someplace else. I never flashed it but I did find one (Team Vicious)
Again ( Add This To Your Signature )
READ BEFORE POST
LOOK WHERE YOU POST
bittermormon said:
Nexus noob here. What is fastcharge? Does it basically remove any USB connection options and increase the charging speed?
Click to expand...
Click to collapse
1 A = 1 Amp
1 mA = 1 Milliamp (.001 Amps)
A charging AC port can give up to 1.5A through a USB cable, but when connected to a regular port (computer, some chargers), it only provides up to 500mA (0.5A).
What fastcharge does is allow the phone to view the USB connection not as a USB hub or computer, but as a devoted AC charger. This adds much Amperage and vastly improves charging. This allows you to plug into a computer and charge at nearly the same speed as your devoted AC charger. It also helps with car chargers, which for some reason can be stingy.
Some Kernels support this, and many roms have the toggle built in. I started loving it using AOKP, thinking it was BS, but it actually works very well. With AOKP and Franco kernel, I could charge my battery fully from car or USB in an hour, double the time it would take without fastcharge.
Only draw back is you lose the ability to transfer files via that USB connection (the connection to computer shows up as "INTF2" instead of "Media Device." No matter how you feel about it, it's great to have the option to suck some extra battery life, especially considering how crucial my phone is to my existence (I wish I was joking). So now when I'm at my friend's, if he has any device which takes a USB A to USB micro b (what droids use) then I don't need a wall charger and it will have nearly the same effect.
I was testing to see if the custom JB Kernels supported this feature, since I know with ICS and GB, the stock kernels wouldn't allow it. This is very exciting as now AOKP can built in the toggle and don't have to stress about how well it works or whether the majority of kernels support it.
look4alec said:
1 A = 1 Amp
1 mA = 1 Milliamp (.001 Amps)
A charging AC port can give up to 1.5A through a USB cable, but when connected to a regular port (computer, some chargers), it only provides up to 500mA (0.5A).
What fastcharge does is allow the phone to view the USB connection not as a USB hub or computer, but as a devoted AC charger. This adds much Amperage and vastly improves charging. This allows you to plug into a computer and charge at nearly the same speed as your devoted AC charger. It also helps with car chargers, which for some reason can be stingy.
Some Kernels support this, and many roms have the toggle built in. I started loving it using AOKP, thinking it was BS, but it actually works very well. With AOKP and Franco kernel, I could charge my battery fully from car or USB in an hour, double the time it would take without fastcharge.
Only draw back is you lose the ability to transfer files via that USB connection (the connection to computer shows up as "INTF2" instead of "Media Device." No matter how you feel about it, it's great to have the option to suck some extra battery life, especially considering how crucial my phone is to my existence (I wish I was joking). So now when I'm at my friend's, if he has any device which takes a USB A to USB micro b (what droids use) then I don't need a wall charger and it will have nearly the same effect.
I was testing to see if the custom JB Kernels supported this feature, since I know with ICS and GB, the stock kernels wouldn't allow it. This is very exciting as now AOKP can built in the toggle and don't have to stress about how well it works or whether the majority of kernels support it.
Click to expand...
Click to collapse
What a spot on post! And, yes, I really like how much AOKP supports, even though I'm not currently using it - who isn't using JB?
Yes, the JB kernels have started to re-implement features as JB is better understood. Franco's is also running great with JB (Official or AOSP).
Please Note: You may forget that you've unleashed the charging potential of whichever connection you're using. Remember, you will need to disable fast charge to use your phone's data connection properly. I'm guilty of forgetting myself from time to time. Nothing like being aggravated at something you did to yourself and can't figure out. lol
kynolin said:
What a spot on post! And, yes, I really like how much AOKP supports, even though I'm not currently using it - who isn't using JB?
Yes, the JB kernels have started to re-implement features as JB is better understood. Franco's is also running great with JB (Official or AOSP).
Please Note: You may forget that you've unleashed the charging potential of whichever connection you're using. Remember, you will need to disable fast charge to use your phone's data connection properly. I'm guilty of forgetting myself from time to time. Nothing like being aggravated at something you did to yourself and can't figure out. lol
Click to expand...
Click to collapse
Are you talking 3G/4G? I did not know it interferes! Does it interfere even when you're not charging? Have you tried Faux Kernel? I really like Franco but many were saying it conflicted with Vicious. Which Franco are you using? New nightly? I saw that he added JB support but the consensus on the Vicious forum is Faux. It seems alright but not as good as I was getting, battery-wise.
This is such an exciting time to be an Android user with the best (at least most supported) phone!
Any way of getting fast charge setting to stick after a reboot? Seems you have to enable it all the time.
Preface:
Although I have been "reading the mail" for a while, I am a new member so I cannot put this in the same thread as the existing wireless mod this is meant to update. Likewise, I cannot link to my pictures directly until I get at least 10 posts submitted so the smaller attached versions will have to do for now. With that said, I see many people are not happy about the lack of native wireless charging support in regards to the T-Mobile Note II (T889). With over 18 years of engineering experience and a T889 myself, I decided to investigate this issue. After 10+ hours of tearing down my own Note II and trying many of the options others have already attempted, I have a few findings.
A. The core design of the T889 is the same as the i317 and N7100. Samsung even uses a mixture of the various device parts to make the T889; including the main system board.
B. The only obvious difference looks to be the actual core processor, which has the hard coded framework (similar to a BIOS) that controls the fundamental parameters of the radio and device capabilities. This framework also takes presentence over any middleware ROM loaded on to the device so there is only so much that can be modified (liberated) without causing too many underlying issues. This method of development is common when creating customized versions of a device for multiple clients while also making sure the FCC part 15 type acceptance regulations here in the USA are adhered to without resubmitting each device multiple times for each client version.
C. In the case of the T889, I believe the ability to facilitate the 802.11 calling feature (either ON or OFF) cost the device its ability to also allow for wireless inductive charging. It may be the stray RFI created by both functions operating at the same time would either not pass FCC type acceptance or the device was never originally type accepted with both features enabled at the same time. Regardless, my overall conclusion is the wireless charging feature in the T889 is disabled on the hardware level and there is no cost effective nor reasonable way to change this.
Other notes:
The above may also explain why the N7100 USB charging board swap doesn't work and why the T889 crashes when loading the home screen; even if a N7100/i317 ROM is loaded on the device. It looks like the processor and/or power management chip is hard-coded to poll the little logic chip on the T889 and i317 charging boards regardless of the ROM. If it does not see that chip (the case with the N7100 USB charging board), it cries foul and triggers a reset (shut down) command. So, it is what it is and we must "skin the cat" a different way.[see image usb_cb_lg.png]
Updated Mod:
The current wireless mod to enable inductance charging on the T889 is a great option, but while ripping my T889 apart, one action item I wanted to do was see if I could make the modification easier and cleaner at the same time. I believe I have achieved this. With my version of the modification, the distance from point A to point B has been reduced to less than 45mm and there is no need to remove or navigate a conductive trace from the charging board/speaker housing assembly. With that said, let's begin. -
* Please proceed at your own risk knowing that you will most likely void your warranty performing this mod. I nor anyone else will be held responsible if you fail to perform this modification correctly and physically damage your device. You have been warned.
- This procedure requires the use of the following tools:
1. A non-conductive and clean work space such as a wood table or natural stone counter top.
2. A soft micro-fiber cloth or pad to lay the device on while working on it.
3. A multi-meter capable of reading resistance in Ohms and DC voltage.
4. A small razor blade.
5. A #0 Phillips head precision screw driver.
6. A small plate to keep the fasteners secure while working.
7. Common case separating pick
8. A professional temperature controlled soldering iron with a pencil tip no larger than 2mm in width – set to no more than 725̊ F.
9. A small roll of rosin core 60/40 solder.
10. 45mm of AWG-30 [0.01" / 0.255mm] or similar sold core vinyl sleeved wire.
11. Fine tip tweezers.
12. Experience and patience.
Now, the good stuff!
- The new location to tap into the +5VDC is on the (+) side of the zener diode located just north of where the charging board header connector feeds the main system board. Form there, it is only 40mm to the positive voltage side of the wireless charging contacts. [see images t889wcmsp.png and t889_wmod_a.jpg]
- This is how is should look like once done... [see image t889_wmod_b.jpg]
- Note the small compression mark caused on the wire when I first tested the casing reassembly. This can be rectified by carefully cutting a small "V" shaped groove in the casing fastener hole cross member. This will also facilitate a 1-2mm gap guide on the inside of the casing wall once reassembly is complete. [see image t889_wmod_c.jpg]
Once done, install your compliant (5vDC @ 1000mAh) inductance receiver plate and you are good to go with a clean voltage line that will be reliable and allow you to charge the T889 via any QI compliant charging pad such as the one made for the Samsung S4.
Have fun and be safe,
Scott
Bye the way, I have also attached a pic (see image t889pcb_sm.png) showing both sides of the T889 main system board with a message on where to get the higher definition version. It is very enlightening regarding what makes up the T889 and what I have been talking about.
Here are some additional pics of the mod working with the new Samsung S4 wireless charger that was on sale last week.
Scott-
What type of wireless charging pad did you use to put in the back of the phone? Links/pics would be great to show a 100% guide.
When placed on the wireless charger, do you get a confirmation popup every time it's placed on it?
How fast is the wireless charging rate? Same as plugging it in?
imaleecher said:
What type of wireless charging pad did you use to put in the back of the phone? Links/pics would be great to show a 100% guide.
When placed on the wireless charger, do you get a confirmation popup every time it's placed on it?
How fast is the wireless charging rate? Same as plugging it in?
Click to expand...
Click to collapse
The receiver pad is a common 5vDC up to 1.0amp "Note2 N7100" QI compliant pad you can find easily on eBay. Since I do not have enough posts yet, I cannot link to the source I used, but again, they are easy to find.
Re: Notification
Since the T889 does not natively support the wireless charging feature, there is no "wireless charging" notification popup present. However, functionally, everything works perfectly fine and the same notifications apply whether you place the T889 on the Samsung charging pad or plug in the traditional USB charging/sync cable.
Wireless charging pad with the T889 OFF:
- The charging pad light first turns ON/Green within 1 second of placing the unit on the pad properly.
- Then, within another 2-3 seconds, the T889 launches the battery icon and begins the charging process.
- After about 30 seconds or so, the battery icon and screen go to sleep and the red charging indicator LED takes over.
Wireless charging with the T889 ON:
- The charging pad light first turns ON/Green within 1 second of placing the unit on the pad properly.
- Then, within another 1-2 seconds, the T889 produces the two-tone (default) audible charging notification with the lightening bolt showing up on the display inside the battery icon.
- The charging process is now active and doing its thing.
Although it acts the same way as charging via the USB port, the efficiency of wireless charging is still in the 75-80% range so in reality and accounting for the circuit overhead that peaks out at 1000mA, my initial finding is the charge rate is about 15% per hour when paired with the stock 3100mA battery (or approximately 6.75 hours for a complete charge). Regardless, it is still pretty snappy and I will test it some more over the coming days.
One thing that should be noted is the 1000mA receiver pad takes up 100% of the marginal space in the T-Mobile rear cover plate so do not try this with anything larger than the standard 3100mA battery unless a deeper rear cover plate can be sourced.
Scott-
One little note, the 1000 Ma can not be achieved with stock kernel, I use Perseus kernel that can tweak the USB charging from 450 ma, to 1000.
For an accurate (more or less) measurement, use Galaxy Charging app from Play Store.
Sent from my SGH-T889 using xda premium
premiatul said:
One little note, the 1000 Ma can not be achieved with stock kernel, I use Perseus kernel that can tweak the USB charging from 450 ma, to 1000.
For an accurate (more or less) measurement, use Galaxy Charging app from Play Store.
Sent from my SGH-T889 using xda premium
Click to expand...
Click to collapse
Thanks for the heads up. I will look into this.
Scott-
Alright, here are the enlightening results of the wireless and USB direct charging current utilizing Galaxy Charging Current Pro v1.6.
As stated, I am going to continue to test the actual charge times more in the coming days. :good:
Scott-
Amazing work. It's always great to see people still tinkering with their devices.
Today, I changed the stock kernel to the Saber variant and I am liking the results. With no others changes or mods, I am now seeing 900mA of the 1000mA the QI receiver pad is spec'd at.
I was also able to charge from 81% to 91% in exactly 25 minutes with the T889 ON, the screen awake, Wi-Fi active, and the phone idling. This would equate to approximately 4 hours and 10 minutes per complete charge, which is very respectable.
Scott-
Just wanted to give thanks to the very in depth" and professional manor of which you take time explaining all of this along with very :thumbup:detailed illustrations.
If you know so much about modifying the hardware in such a way to achieve this, you could very well be the guy every android owner has been waiting for
to maybe one day software mod these phones to one day get 3-4 day batt life regardless of any battery mah size
Once again thanks for the info
Sent from my SGH-T889 using xda premium
lojak29 said:
Just wanted to give thanks to the very in depth" and professional manor of which you take time explaining all of this along with very :thumbup:detailed illustrations.
If you know so much about modifying the hardware in such a way to achieve this, you could very well be the guy every android owner has been waiting for
to maybe one day software mod these phones to one day get 3-4 day batt life regardless of any battery mah size
Once again thanks for the info
Sent from my SGH-T889 using xda premium
Click to expand...
Click to collapse
Thanks, but I am more on the hardware side and not the software arena. Plus, this mod concept was originally not my idea so I cannot take complete credit for it. I simply investigated the situation and found yet another way to achieve the end result. Regardless, the battery chemistry is just not there yet so if you want 3-4 day operation between traditional charges, I suggest looking into one of these new solar and other alternative charging options.
http://www.hongkiat.com/blog/extraordinary-smartphone-chargers/
For now, I am back to enjoying this current QI solution and have established a repeatable charging cycle time that is within 5 minutes on each benchmark. With the Saber kernel allowing for 900mA of wireless charging current to make it through the circuit, the 0-2% to 100% charge time looks to be 4 hours, 25 minutes (+/-5 min). My latest charge cycle that just completed is shown below.
I'm happy -
Scott
Thanks for this info.
I have an AT&T SGH-I317 with a wireless charging pad. It works but is fairly slow charging at about 460 mA. I've read that the original mod with the Perseus kernal would allow the device to charge faster.
Before I jump into it I'd like some confirmation that this mod would give my wireless charging a boot on my AT&T Note II. I haven't found a lot if complete info and am concerned.
Thanks...
RojasTKD said:
Thanks for this info.
I have an AT&T SGH-I317 with a wireless charging pad. It works but is fairly slow charging at about 460 mA. I've read that the original mod with the Perseus kernal would allow the device to charge faster.
Before I jump into it I'd like some confirmation that this mod would give my wireless charging a boot on my AT&T Note II. I haven't found a lot if complete info and am concerned.
Thanks...
Click to expand...
Click to collapse
As your i317 is already QI capable, then there is no need to perform this mod. Your specific focus should be confirming the following before flashing the kernel:
1. Is your QI charging (transmitting) platform rated at 2A (input) with an effective output of approx. 1A? Likewise, is the wall adapter feeding the pad rated at up to 2A?
2. Is the QI receiving pad mounted on your i317's rear case panel or the battery rated at 1000mA @ 5V? [Anything lower like 700mA will obviously limit your charging rate, which results in longer charging times].
I have not tested the Perseus kernel, but the Saber kernel on my T889 does liberate the higher charging rate as long as the hardware TX/RX pads support it (as covered above). I average about 980mA, which is within 5% of the rated peak for my Samsung charging platform.:good:
Scott-
SGBE said:
As your i317 is already QI capable, then there is no need to perform this mod. Your specific focus should be confirming the following before flashing the kernel:
1. Is your QI charging (transmitting) platform rated at 2A (input) with an effective output of approx. 1A? Likewise, is the wall adapter feeding the pad rated at up to 2A?
2. Is the QI receiving pad mounted on your i317's rear case panel or the battery rated at 1000mA @ 5V? [Anything lower like 700mA will obviously limit your charging rate, which results in longer charging times].
I have not tested the Perseus kernel, but the Saber kernel on my T889 does liberate the higher charging rate as long as the hardware TX/RX pads support it (as covered above). I average about 980mA, which is within 5% of the rated peak for my Samsung charging platform.:good:
Scott-
Click to expand...
Click to collapse
Thanks for the reply.
I have read that the charge rate is limited by the device to something like 466mA. Mine charges at 460. Some say the kernel will raise it the others say the kernel alone won't do it, a hardest mod (like this) is required.
To answer your questions:
1. Transmitter Nokia DT-900 output 750mA.
2. Receiver rated at 650mA
I'd be happy to get the charge rate around 600mA. I know my setup I'd not capable of charging at 900mA, but would like to do better than the 460mA I'm now... getting off possible.
If I can get it charging rate higher, I'd look into getting a 1000mA receiver, but won't be getting a new transmitter until the prices drop. I was able to get several Nokia charges for just under $20a piece.
When I get home I will try Saber kernel.
Sent from my Nexus 7 using Tapatalk 4
Try the custom kernel since that does control the charging manager functions. If the change is marginal, your RX pad may be actually functioning like a 500mA rated pad. Hopefully, you will see something closer to 600-640mA with your setup (even if the charge time will not be significantly reduced). If anything, invest in a good RX pad that is rated up to the 1000mA so you know you are able to accept any level energy up to the 1A regardless of the charger you use now or buy later.
SGBE said:
Try the custom kernel since that does control the charging manager functions. If the change is marginal, your RX pad may be actually functioning like a 500mA rated pad. Hopefully, you will see something closer to 600-640mA with your setup (even if the charge time will not be significantly reduced). If anything, invest in a good RX pad that is rated up to the 1000mA so you know you are able to accept any level energy up to the 1A regardless of the charger you use now or buy later.
Click to expand...
Click to collapse
With Saber Kernel 39.3 I am somehow getting a reading of 899mA, not sure how, as neither my receiver or transmitter should allow this. Though the pic on the FastTech site showed a green receiver pad that had 5v650mA printed on it, the one I got doesn't say anything, so it may be capable of up to 1000mA. Even so my Nokia should not be ab;e to supply enough to charge at the reading I'm getting.
Well, I've always used Perseus Kernel because Saber did not support my 64GB MicroSD card. Flashed Saber Kernel 39.3 and it does support my 64GB MIcroSD, Even the stock saber kernel that comes with Jedi X17 dose not support my exfat 64GB card. So I guess I'm happy.
We'll see what happens. Thanks for the help, it is greatly appreciated!
Very cool! Your charging time should be greatly reduced if eveything is being reported correctly by the app. Please confirm once you test a few cycles.
Sent from my SGH-T889 using Tapatalk 4
SGBE said:
Very cool! Your charging time should be greatly reduced if eveything is being reported correctly by the app. Please confirm once you test a few cycles.
Sent from my SGH-T889 using Tapatalk 4
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Click to collapse
My battery drain seemed to be much greater with the Saber Kernel vs the Perseus kernel I was using. So I went back to the Perseus kernel and even the though it reads 466mA vs Sabers 899mA they both seem to charge at about the same rate (10-12% per hour). I didn't do a real detailed comparison so the Saber my get an extra percent or two per hour, but that means little if it drains the batter much faster.
Maybe I'll try saber 39.3 again to double check the drain and charge times.
on a sad note I cracked my screen again. Luckily the replacement screen price has dropped considerably. I paid less than half of what I did the first time I had to replace it.
SGBE said:
Today, I changed the stock kernel to the Saber variant and I am liking the results. With no others changes or mods, I am now seeing 900mA of the 1000mA the QI receiver pad is spec'd at.
I was also able to charge from 81% to 91% in exactly 25 minutes with the T889 ON, the screen awake, Wi-Fi active, and the phone idling. This would equate to approximately 4 hours and 10 minutes per complete charge, which is very respectable.
Scott-
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SGBE, thanks for all the info you've provided on this thread. I have a few request, what settings are you using in the saberkernel and where did you go to change these settings? Thanks again!
Sent from my SGH-T889 using xda premium
I'm having problems getting the solder to stick to the resistor up by the charging contacts. I'm afraid if I try much more the resistor will be toast. Can I solder directly to the top contact and it would still work?
..Or Charging rate be reduced and/or controlled. By a custom kernel Or anything? Please Suggest.
Thank You
How about just using the regular not fast charger with strength (A) that you prefer? With stock 2A rated charger charging takes 3h & cuple of minutes (if you don't use the phone). Guess even 1A charger should be sufficient for charging it over night but it will take about 6h for full recharge.
Im on Resurrection remix as we know RR based on Lineage
and support QC 3.0 indeed
Thanks, brought a 1.5A charger. To see how much time it takes. For disabling it permanently for a Rom, there is no way?
It's possible in kernel & not by user but opposite to you most blocks around hire will actually want to have it enabled. So just using preferred charger actually best fits all, besides slow ones are really cheap this day's & most people have them from their older phones.
Best regards.
Hi,
I'm using some Nexus 7 (2013) with Android 4.4.4 as control panels, being 24/7 powered with an AC charger. After ~2 years operation, the batteries in my Nexus 7s expanded dramatically to the point I have to replace them. I guess it's due to them being constantly held at maximum level (4.25V) at a moderate temperature ~5°C above ambient. Since I don't really use the battery - and the Nexus 7 won't boot with the battery detached (tried it), I'm looking for a way to disable the battery charging via ac (and usb/wireless) completely via software, so I can make my own charging logic that tops the battery at ~3.80V which should make it way more happy.
I already did some research and found https://android.stackexchange.com/questions/54902/disable-usb-charging or https://android.gadgethacks.com/how...oid-device-avoid-excess-battery-wear-0176280/
Command "dumpsys battery set ac 0" or "dumpsys battery set status 4" didn't have an effect.
The file "/sys/class/power_supply/battery/charging_enabled" doesn't exist on the Nexus 7 (2013).
I do have root...
Can someone help me out?
Thx
Edit: Problem solved with custom kernel, see post #10
That funcionality must be enabled in the kernel. However, I guess is not possible because it must be supported by the hardware, which is not the case
Maybe you can detach the battery and supply about 4 volts by using and external power supply and voltage regulator connected to the board pins
I am interested on this too...
bamsbamx said:
it must be supported by the hardware, which is not the case
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Click to collapse
Do you know for sure? Do you have any information about the power management chips used and/or schematics?
bamsbamx said:
Maybe you can detach the battery and supply about 4 volts by using and external power supply and voltage regulator connected to the board pins
Click to expand...
Click to collapse
Using an actual regulated voltage source is not a good idea, since the device will try to charge it.
Best fake battery might be a capacitor. I've tried a 100µF cap and it tricked the Nexus 7 into thinking a proper battery is connected and it bootet. But after a second it did shut off. I guess it actually tried to drain the battery despite the fact that a AC supply was connected and thus the cap drained immediately.
A supercap might work, but I don't have one. I also don't know if slim ones actually exist that would fit into the case.
Another mod would be to place two antiparallel schottky diodes between the plus terminal and the battery. This way it would only charge to ~4.0V, but as soon the charging stops, the battery would read ~3.7V and I guess that would drive the charging circuit crazy.
Also, I'd prefer to not do any hardware mods... I have lots of these devices
Edit: Actually, with a 1500µF cap the boot screen appears and I can also enter recovery. But as soon as android starts to boot, the voltage collapses and the device reboots.
bamsbamx said:
Maybe you can detach the battery and supply about 4 volts by using and external power supply and voltage regulator connected to the board pins.
Click to expand...
Click to collapse
Connecting power directly to the motherboard, presumably without a battery and the data lines, has not been tested, but removing battery from its control PCB and connecting a 5V power supply instead works fine.
RFZ said:
Do you have any information about the power management chips used and/or schematics?
.....
Using an actual regulated voltage source is not a good idea, since the device will try to charge it.
......
A supercap might work, but I don't have one.
Click to expand...
Click to collapse
Here is some info on battery control IC.
If the regulated voltage source is 5V (vs 3.7-4.2V), the device will have no reason to charge it, but "charging" a power supply is harmless anyway.
A supercap is still not good enough as the initial boot up current peaks at 1A and takes several seconds, while an external power supply on the USB port can contribute only a small portion of it. Another option is a different battery - the Nokia battery never expanded after years of being constantly powered with an AC charger.
Applying 5V to the battery protection pcb that expects a Li-Po isn't the first idea I'd have... According to ifixit, the N7 uses a PM8921 Battery Management Chip. It's rated maximum for V_bat is 4.5V (section "3.2 Recommended operating conditions" https://developer.qualcomm.com/down...er-management-module-device-specification.pdf )
Also, I'd prefer to keep the battery. It is still useful in power outage scenarios.
An interesting idea however is to modify the chip on the battery itself. Maybe I can program it to a lower maximum voltage and the PM8921 will then respect that?
I also found the kernel driver for the PM8921
https://android.googlesource.com/ke...3.4-kitkat-mr0/drivers/power/pm8921-charger.c
It looks like it supports stopping the charge... But I don't know how if it's possible to use that...
After receiving a logic analyzer, I had a look at the I2C communication with the bq27541-G1 chip on the battery.
The Nexus 7 only reads Voltage( ), StateOfCharge( ), Temperature( ), AverageCurrent( ) and Flags( ) during boot and when the usb plug is (un)plugged. I was hoping it would read parts of the configuration of the bq27541-G1, e.g. the Charging Voltage, to get parameters for the power management IC.
I also read other devices on the bus besides the bq27541-G1 (0xAA/0xAB): These are i2c addresses 0x72/0x73, 0xD4/0xD5 and 0xEE/0xEF
I guess I will have to take a different approach... Modifying the kernel.
Actually, the problem is, I really don't know what a kernel is or does in the context of a complete android system. I never looked at different kernels and what they might offer. However, since the stock kernel (right?) doesn't expose any access to the Nexus power management IC, I will have to expose it myself... As far as I can tell, the ability is there ( https://android.googlesource.com/ke...3.4-kitkat-mr0/drivers/power/pm8921-charger.c ) and others, like "Timur's Kernel", seem to have been able to change parts of the power management within the kernel.
Is there someone of you out there who has some experience in compiling his own kernel and can tell me if that's the proper way to go?
RFZ said:
I guess I will have to take a different approach... Modifying the kernel.
Actually, the problem is, I really don't know what a kernel is or does in the context of a complete android system. I never looked at different kernels and what they might offer. However, since the stock kernel (right?) doesn't expose any access to the Nexus power management IC, I will have to expose it myself... As far as I can tell, the ability is there ( https://android.googlesource.com/ke...3.4-kitkat-mr0/drivers/power/pm8921-charger.c ) and others, like "Timur's Kernel", seem to have been able to change parts of the power management within the kernel.
Is there someone of you out there who has some experience in compiling his own kernel and can tell me if that's the proper way to go?
Click to expand...
Click to collapse
This one is for building AOSP kernel for Sony devices. However, the script might help you in the build: https://github.com/bamsbamx/aosp-sony-kernel/blob/aosp/LA.UM.5.7.r1/utils/build.sh
Keep in mind you will also need a toolchain.
Here is what the kernel looks like: https://github.com/bamsbamx/aosp-sony-kernel
Although it wont be easy at all if you never built one
Thx. I don't think building a kernel is that hard. For the Nexus 7, this should be well documented. ( e.g. http://pete.akeo.ie/2013/10/compiling-and-running-your-own-android.html and https://source.android.com/setup/building-kernels )
The other problem is to find out where to start modifying the stock kernel. I still think https://android.googlesource.com/ke...3.4-kitkat-mr0/drivers/power/pm8921-charger.c is the right place. Probably just overwriting pdata->max_voltage in https://android.googlesource.com/ke...itkat-mr0/drivers/power/pm8921-charger.c#4539 to 4000 does the trick. Or I have to find out where this platform data initially comes from.
Biggest problem is, without having any experience in compiling a kernel, I have no Idea how to debug the changes - e.g. how to look at the data pdata gets initialized with.
Okay, long story short: It works! :victory:
Actually, the Nexus 7 (2013) doesn't use "pm8921-charger" at all... It's using "smb345-charger" (SMB345ET-1850Y IC, haven't found a datasheet though ).
In smb345-charger.c the #define FLOAT_VOLT_43V 0x28 actually defines the max charging voltage. Despite the fact that I don't have a datasheet, I'm pretty sure the value represents the charging voltage in 20mV increments, starting at 3.50V (0x00) up to 4.76V (0x3F). 0x19 results in a charging voltage of 4.0V etc...
Since I'm obviously not able to compile my own kernel in just one day, I have to thank @pfent who did this for me :highfive:
The patched code can be found here on github.
What's the result? Well, the Nexus 7 (2013) now will top out charging at 4.0V and stay there. I hope this will noticeably increase the lifetime of the battery and especially prevent it from swelling. I don't know how or if this might effect / confuse the gas gauge meter on the battery or the devices capacity calculations, but I think it will be fine. We'll see in 1-2 years
Edit: Attached a charging curve screenshot. The battery is charged to 4.0V, then no current is flowing in or out the battery.
Edit 2: Looks like other kernels implemented similar features: https://github.com/flar2/flo-Elemen...7067e030e/drivers/power/smb345-charger.c#L958
After installing Magic Charging Switch disable charging.
RFZ said:
Hi,
I'm using some Nexus 7 (2013) with Android 4.4.4 as control panels, being 24/7 powered with an AC charger. After ~2 years operation, the batteries in my Nexus 7s expanded dramatically to the point I have to replace them. I guess it's due to them being constantly held at maximum level (4.25V) at a moderate temperature ~5°C above ambient. Since I don't really use the battery - and the Nexus 7 won't boot with the battery detached (tried it), I'm looking for a way to disable the battery charging via ac (and usb/wireless) completely via software, so I can make my own charging logic that tops the battery at ~3.80V which should make it way more happy.
I already did some research and found https://android.stackexchange.com/questions/54902/disable-usb-charging or https://android.gadgethacks.com/how...oid-device-avoid-excess-battery-wear-0176280/
Command "dumpsys battery set ac 0" or "dumpsys battery set status 4" didn't have an effect.
The file "/sys/class/power_supply/battery/charging_enabled" doesn't exist on the Nexus 7 (2013).
I do have root...
Can someone help me out?
Thx
@VR25
After installing Magic Charging Switch its disable charging. I am tried to disable/uninstall Module from magisk but still my mobile not charging. Disconnecting again and again.
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Click to collapse
Dinesh 1C0N said:
@VR25
After installing Magic Charging Switch its disable charging. I am tried to disable/uninstall Module from magisk but still my mobile not charging. Disconnecting again and again.
Click to expand...
Click to collapse
What device is it?
If it's a Nexus 7, try echo 1 >/sys/devices/i2c-0/0-0055/battery_smbus.
BTW, aren't you in the wrong thread?