Develop Bugs

U2 vs U9

This is going to sound ridiculous, but I have to say it anyway.
I have a Samsung Galaxy S2 (SGH-i777), and I have two charging cables. A U9, and a U2.
When I charge the phone overnight with the U9 cable, I get a 100% rating on the charge, but the battery dies VERY fast. I unplug the phone at 7am, and it's down to 70% by 10am with very little use.
When I charge the phone overnight with the U2 cable, I get a 100% rating on the charge as well, but then the battery dies very slowly, the way I prefer it. I can use the phone moderately all day, and still have a good 30-40% when I get home after 5pm.
Clearly, I use the U2 cable, as this achieves my goal. My question is, why does it work this way? Is there something wrong with the U9 cable? Does it charge the battery differently than the U2?

Check what kind of charging the phone recognize "USB" or "AC". If it is USB the charging is slower (450mA) when AC is faster (650mA).

flash608 said:
Check what kind of charging the phone recognize "USB" or "AC". If it is USB the charging is slower (450mA) when AC is faster (650mA).
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I'm not quite sure what you mean. Is there a place in the menu of the phone to check for this?
I used to use the wall-outlet adapter with the U9 cable. Now I am using the same wall-outlet adapter with the U2 cable.

It`s hidden in Settings -> About Phone -> Status -> Battery Status (AC/USB)

Shibblet said:
I'm not quite sure what you mean. Is there a place in the menu of the phone to check for this?
I used to use the wall-outlet adapter with the U9 cable. Now I am using the same wall-outlet adapter with the U2 cable.
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When you connect the usb cable the phone says that is connected like a media device and a usb symbol appear in status bar and notification area, it means that are charging at 450 mAh (like usb connected to PC), but if only see a charging battery indicator then is charging at 650 mAh (like Power AC Adapter).
But I really dont know if the charge duration is affected, maybe is overcharging your battery. Try this, charge until 100% with both, but disconnect it when the phone says that charge is complete and try. Maybe with the time the battery is overcharged and has more battery with one of the cables.

At a molecular level, the slower charging is more thorough and actually deposits more charge (energy) into the battery, which is why a slow charge rate results in a better performing cell or battery. Remember, batteries (or cells; a battery is just a collection of cells) change energy from chemical to electrical when providing power, and accept energy when being charged by converting electrical energy to chemical energy. That chemical change doesn't happen instantaneously, and is why a slow charge can actually raise a cell or battery's energy level higher.
Generally, the charger measures the charge state of the battery by the voltage of the cell or battery, and charging slowly allows the charge to more thoroughly dissipate through the cell. Rapidly charging, on the other hand, builds potential (voltage) quickly, but the quick charging doesn't allow the chemical change to occur thoroughly throughout the cells, and misleadingly indicates a higher voltage (charge state) than has actually occurred.
Think of the game of Tetris: When the blocks (incoming electrons) are falling slowly, it's easy to pack them tightly and fit more into the play area (battery). When they're coming in quickly, eventually you become unable to fit them all tightly without leaving voids, and the height of the stack (perceived charge level, or voltage) reaches the threshold without being fully packed (charged).
I hope this helps, four years after the question --Mike Jernigan, Greensboro

EightOhMike said:
At a molecular level, the slower charging is more thorough and actually deposits more charge (energy) into the battery, which is why a slow charge rate results in a better performing cell or battery. Remember, batteries (or cells; a battery is just a collection of cells) change energy from chemical to electrical when providing power, and accept energy when being charged by converting electrical energy to chemical energy. That chemical change doesn't happen instantaneously, and is why a slow charge can actually raise a cell or battery's energy level higher.
Generally, the charger measures the charge state of the battery by the voltage of the cell or battery, and charging slowly allows the charge to more thoroughly dissipate through the cell. Rapidly charging, on the other hand, builds potential (voltage) quickly, but the quick charging doesn't allow the chemical change to occur thoroughly throughout the cells, and misleadingly indicates a higher voltage (charge state) than has actually occurred.
Think of the game of Tetris: When the blocks (incoming electrons) are falling slowly, it's easy to pack them tightly and fit more into the play area (battery). When they're coming in quickly, eventually you become unable to fit them all tightly without leaving voids, and the height of the stack (perceived charge level, or voltage) reaches the threshold without being fully packed (charged).
I hope this helps, four years after the question --Mike Jernigan, Greensboro
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4 year? You waited 4 year ???

Is there a way to turn off the fast charging in the OS?

I plan to use this phone for many years, so I'm worried that the fast charging might do damage to the battery in the long term or shorten its lifespan, so I'd rather charge it "slower". Is there a way to turn off the fast charging in the OS? Or is my worry unsubstantiated?

513263337 said:
I plan to use this phone for many years, so I'm worried that the fast charging might do damage to the battery in the long term or shorten its lifespan, so I'd rather charge it "slower". Is there a way to turn off the fast charging in the OS? Or is my worry unsubstantiated?
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You made my night... Slower charger kills battery not fast charging.. fast charge save battery to be honest. And you dont have to be worry since the batteries now are LI-lon . Go get info in google about the batteries . All i can say you got infos wrong.
Sent from my ONEPLUS A3003 using XDA-Developers mobile app

Agree with previous post. But if it makes you feel better, just don't use a dash charger...
Very simple.

lummujaj said:
You made my night... Slower charger kills battery not fast charging.. fast charge save battery to be honest. And you dont have to be worry since the batteries now are LI-lon . Go get info in google about the batteries . All i can say you got infos wrong.
Sent from my ONEPLUS A3003 using XDA-Developers mobile app
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OK. I didn't know.
I was speaking from my past experience with Samsung Galaxy Note 4. I bought couple of original Samsung batteries and rotate them throughout daily usage. I noticed a significant difference in battery life comparing the ones that I used fast charge on vs the ones I didn't. After that I stick to NOT using fast charge.
Of course, that's nothing scientific. And Samsung uses a different fast charge mechanism (higher voltage) than OnePlus (higher current), so there could be difference there too.

Because Dash Charge seems to be re-labeled Vooc charging from OPPO, I can tell you, that the last two years with charging minimum one times every day, there is no bad effect on the battery (still the first one).
Sent from my Find7 using XDA-Developers mobile app

513263337 said:
OK. I didn't know.
I was speaking from my past experience with Samsung Galaxy Note 4. I bought couple of original Samsung batteries and rotate them throughout daily usage. I noticed a significant difference in battery life comparing the ones that I used fast charge on vs the ones I didn't. After that I stick to NOT using fast charge.
Of course, that's nothing scientific. And Samsung uses a different fast charge mechanism (higher voltage) than OnePlus (higher current), so there could be difference there too.
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Samsung devices are notorious for killing batteries and its more likely hardware than it is the battery itself, u will be fine

I have a similar question: does it make any problem if I leave the phone in (dash) charge for the whole night? I mean, if I sleep for 7hrs I'll have 1h of fast charging and 6hrs of nothing-but-charger-heating. Will this habit hurt the phone's battery or the charger itself?

513263337 said:
I plan to use this phone for many years, so I'm worried that the fast charging might do damage to the battery in the long term or shorten its lifespan, so I'd rather charge it "slower". Is there a way to turn off the fast charging in the OS? Or is my worry unsubstantiated?
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I use Samsung 1.5 Amp charger and keep my battery between 40% to 80%
I think these are best for long term usage.

repsol89 said:
I have a similar question: does it make any problem if I leave the phone in (dash) charge for the whole night? I mean, if I sleep for 7hrs I'll have 1h of fast charging and 6hrs of nothing-but-charger-heating. Will this habit hurt the phone's battery or the charger itself?
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I used a samsung S3 before and overnight charging killed my battery! Bless samsung for making battery removable on S3!
If i were you, I wouldn't leave my precious OP3 on an all-night charge.

iam_adarsh said:
I used a samsung S3 before and overnight charging killed my battery! Bless samsung for making battery removable on S3!
If i were you, I wouldn't leave my precious OP3 on an all-night charge.
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Well, it was my first thought, but everyone in this topic is telling me that OP works different than Samsung!

iam_adarsh said:
I used a samsung S3 before and overnight charging killed my battery! Bless samsung for making battery removable on S3!
If i were you, I wouldn't leave my precious OP3 on an all-night charge.
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that's the problem of the charger or the phone itself. thecharger is designed not to charge when the battery is full. What I want to say is you experienced an accident and sorry for you.
The most serious threat to the battery is high temperature. OnePlus 3 reduce the charging heat by its dash charge. The dash charge pushes low voltage directly to the phone, which mitigates the heating problem by pushing high electric current and making the voltage transition process in dash charger. Most of other phones still use high voltage because they fail to create high current. recalling the physics in high school, the power is current multiplied by voltage and energy equals to power multiplied by time. than you would understand the powerful feature of dash charge

dlhxr said:
that's the problem of the charger or the phone itself. thecharger is designed not to charge when the battery is full. What I want to say is you experienced an accident and sorry for you.
The most serious threat to the battery is high temperature. OnePlus 3 reduce the charging heat by its dash charge. The dash charge pushes low voltage directly to the phone, which mitigates the heating problem by pushing high electric current and making the voltage transition process in dash charger. Most of other phones still use high voltage because they fail to create high current. recalling the physics in high school, the power is current multiplied by voltage and energy equals to power multiplied by time. than you would understand the powerful feature of dash charge
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The power is current multiplied by voltage so what's the difference between high current mutiplied by low voltage versus low current multiplied by high voltage ?
2V x A = V x 2A

lapocompris said:
The power is current multiplied by voltage so what's the difference between high current mutiplied by low voltage versus low current multiplied by high voltage ?
2V x A = V x 2A
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qc3.0 uses low current and high voltage. Dash uses high current and low voltage. As a result, they have similar power and both charge quickly. However, the heating problem is more serious for qc 3.0. The difference of the battery voltage and charger voltage is the leading factor that determines the transition efficiency. The bigger the difference is, the more heat charging process generates.
So~ you could look up for qc3.0. for mi 5, it has three adaptive mode: 5V2.5A、9V2A、12V1.5A. for dash, we have 5V4A

repsol89 said:
I have a similar question: does it make any problem if I leave the phone in (dash) charge for the whole night? I mean, if I sleep for 7hrs I'll have 1h of fast charging and 6hrs of nothing-but-charger-heating. Will this habit hurt the phone's battery or the charger itself?
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There is no problem with leaving your phone on the charger. I do this with every phone since years.
If people experience something bad with it, their phone or battery are broken. The current tech just keeps the battery at full capacity once it's full. Never had any problem.

So many "opinions" but mostly incorrect. The answer to the OPs question is that you don't have to worry about quick charge destroying your battery. It will not have significant impact on your battery capacity. I would have been more worried about breaking the usb type-c port(see point 2 below). All things considered, after 2-3 years you will probably buy a new phone anyway and also you can always buy a replacement battery cheap. But you can simply use a normal charger which delivers <3A with 5V so you don't have to worry about anything.
1- Slow charge does not damage lithium-ion chemistry batteries. You can read about lithium-ion charging here. But neither fast charge will damage lithium-ion as long as the battery temperature is not extremely high. Also temperature at different charge stages effect the capacity decrease (source) But you will be fine as long as the battery temperature is less than 45C. The charging IC should stop the charging process if it exceeds it anyway.
2- Qualcomm's quick charge is much better than voop/dash charge from an engineering standpoint. This is why also USB organization's power delivery (PD) standard uses similar scheme. The problem is the cable and the connector. The maximum allowed current at 5V is 3A with usb type-c connector (source). If you provide more current, you need to use a thicker cable(dash/vooc cables). But you can't change the connector, and it may damage your connector in the long run to use 3+A currents to charge. Because there is a contact resistance (R) and the power lost in the connector is square of current (I) times R. Meaning R*I^2, it will wear off the connector faster. This is why some companies with some engineering skills opt in to use higher voltages instead of higher currents.
3- You can't push more current to lithium-ion battery than it accepts. The maximum current is voltage delta (between charging voltage and battery voltage) divided by internal resistance. This is why you can charge empty battery much faster. If you use an app like Ampere from play store, you can see the voltage of your battery before and after you plug in your charger. If you plug in a normal charger, you will see that it goes up a little bit. If you plug a quick charger it goes up to ~4.35V
4- Yes, there is conversion inefficiencies for quick charge inside the phone, and it will warm up the "phone" and battery only indirectly. The conversion IC are normally >90% efficient (source). This does not mean that your battery will be destroyed. It is perfectly fine to charge lithium-batteries with up to 45C temperatures (source).
4- If overnight charging killed your battery, your battery was faulty (or you had 3rd party battery?). The battery should be capable of holding 4.35v charge. You would need to store battery at 4.35V full charge for over 3 months to loose 20% capacity (http://batteryuniversity.com/learn/article/how_to_store_batteries). Having full charge few hours overnight won't destroy it unless your battery or device is faulty.
With all this information, I would rather opt in for USB-PD/Qualcomm Quick Charge solutions than VOOC/DASH solutions. I think eventually only USB-PD will remain and everybody will use it as a standard only.

Crazy charging speeds

So I've noticed my 3xl is crazily boosting power to the phone when charging. I've seen it go all the way charging at 35watts until it reaches 10% then it slows down at 22-25watts until it kind of reaches 25-30% and then it goes to at 15-18watts until it reaches 100% which is lame.
I've read the charger can deliver 65watts and I've used it to charge a laptop which is incredibly fast and it charges my Xiaomi mi pad 4 plus at 22watts.
Why can't Google lock it at somewhere between 25-35watts? How's your charging? Is there any mod/way to charge it more rapidly?

The reason high speed charging cannot be maintained is due to battery physics (or... chemics). When charging battery with high power, you actually stress the battery a lot which will reduce the "total life" of battery. This reduce is (partly) due to the high temperature associated with high current (the battery voltage is pretty fixed around 3.8~4.2V, thus high power=high current) and this high temperature put a lot of stress on battery materials cause shortening of total life.
Also, if keep high power charging too long, the battery will have risk of explosion (for various reasons... High temperature is only one of the them) for example, one of the temporary solution Samsung implemented for Note 7 on fire issue is limiting the charge power, to reduce to risk of catching fire. Big company with a lot at stake like Google usually will not trade safety for anything (there are exceptions.) This is why high speed charging is limited. (sometimes hardware limited for safety reason).

isthatxavier said:
So I've noticed my 3xl is crazily boosting power to the phone when charging... I've read the charger can deliver 65watts and I've used it to charge a laptop which is incredibly fast...?
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65 watts? Not the charger that comes with the phone. Read the output (tiny) label on the stock charger). So maybe you are using a different, badass? USB-C PD charger that supports higher charging rates, but the PD protocols our phones accept are theoretically 18 watts max: [email protected]=18w, [email protected]=15w and legacy [email protected]=10w. You will not see higher than that, and it is regulated by the phone irrespective of the charger you have. The phone's charging amperage curve starts high at very low battery capacity and then tapers off pretty quickly. If your display says "charging rapidly" then you are getting the max rate you can achieve. Hope this helps.

Question Battery temperature while charging

Hi. I have the Indian version of the device, which is Mi 11x 6|128GB variant. I noticed while charging, Accubattery shows battery temps of 45 46 degrees Celsius (113 Fahrenheit). I find that not normal for a new phone. I'm coming from a Poco F1 which had a SD845, so here are my doubts:
1. Does all flagship class SoCs heat up that much during charging? But my Poco F1 didn't.
2. Is there something wrong in my unit or is it faulty cooling implementation on the entire Redmi K40 lineup?
3. Can I expect this issue to become a little less in the future after some updates to alter SoC clock speed or something?
Thanks for reading.

Thats normal if you use the included 33W charger, the battery naturally heats up while charging, the fatest you charge the battery the more heat it produces. is always recommended to not heavily use the phone while in charge. just for the sake of doubt you can try use a 5W charger and see if it heats up while charging slowly, (it should be hot just a little).

What's the ambient temperature?
Is it fast charging? Which typically produces a,fair amount of waste heat.
If it's start temperature is 99F it will climb into the triple digits.
You want the battery to be above at least 72°F at charge start to prevent the possibility of Li plating.
While it may be normal for this phone, you are beating the battery. It's been reported that high temperatures during fast charging can promote Li plating.
Cool it once it reaches 99F, with a fan and/or a damp microfiber cloth.
On my Samsung it will stop charging if it goes above about 102F. Samsung tends to be conservative with their charging parameters.
Not a bad thing as it lengthens battery lifespan and reduces the chances of a thermal runaway event.

GranoTurc00 said:
Thats normal if you use the included 33W charger, the battery naturally heats up while charging, the fatest you charge the battery the more heat it produces. is always recommended to not heavily use the phone while in charge. just for the sake of doubt you can try use a 5W charger and see if it heats up while charging slowly, (it should be hot just a little).
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I'll try this with my Poco F1 charger and let you know what I find

Ambient here is
blackhawk said:
What's the ambient temperature?
Is it fast charging? Which typically produces a,fair amount of waste heat.
If it's start temperature is 99F it will climb into the triple digits.
You want the battery to be above at least 72°F at charge start to prevent the possibility of Li plating.
While it may be normal for this phone, you are beating the battery. It's been reported that high temperatures during fast charging can promote Li plating.
Cool it once it reaches 99F, with a fan and/or a damp microfiber cloth.
On my Samsung it will stop charging if it goes above about 102F. Samsung tends to be conservative with their charging parameters.
Not a bad thing as it lengthens battery lifespan and reduces the chances of a thermal runaway event.
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Ambient here is 86 Fahrenheit and above. While charging the phone, I don't even use it. I just put it face down on the screen so that the heat dissipation is faster from the back surface. But still it reaches those temperatures and is making me doubt the QC process of Xiaomi in this case.

TweaknFreak said:
Ambient here is
Ambient here is 86 Fahrenheit and above. While charging the phone, I don't even use it. I just put it face down on the screen so that the heat dissipation is faster from the back surface. But still it reaches those temperatures and is making me doubt the QC process of Xiaomi in this case.
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It may dissipates more heat through the display.
Never use a phone while charging as it skews the charge cycle parameters.
Simply cool as I described or don't use fast charging.
You can also use partial charge cycles like 40-60%. That's also part of the range the battery pulls high current and heats up.
If I see my battery temp climb above 100F I will stop the charge and hit it up a little latter.
For my Samsung the optimum battery temp range for fast charging is 85-100F. Outside of that range fast charging may not always engage or stay engaged. However in that ambient temperature range I need to some form of cooling when fast charging if I want to maintain a temperature under 100F.
Always keep an eye open for case swelling which indicates a battery failure. Replace it immediately if that happens.
It becomes more likely as the battery ages or if exposed to temperature/current extremes. I just replaced a failed battery at the 1.5 year mark on my Note 10+.
Fun, isn't it

I just checked the charging with my Poco F1 charger which is 18W. The portion just below the camera module heats up the most. And the temperature between charging with the 33W charger and 18W poco charger are same. At least that's what Accubattery says. I'm replacing this device for sure, let's see how the replacement device works out.

TweaknFreak said:
I just checked the charging with my Poco F1 charger which is 18W. The portion just below the camera module heats up the most. And the temperature between charging with the 33W charger and 18W poco charger are same. At least that's what Accubattery says. I'm replacing this device for sure, let's see how the replacement device works out.
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If the temperature is the same than it's not fast charging. Fast charging generates much more heat however even while it's enable the charge rates vary due to temperature, charge state and battery condition.
For instance between 80-100% the charge rates will be about the same. This may start as low as at 70% or even lower if the charging parameters aren't optimum.
The easiest way to tell is with an app like Accubattery. Put it on the charge page then use the power button to turn off the screen. Start charging. You have about a second if you turn the screen on to see the screen off charging milliamp figure. The charging log also tells what was happening but not when it happened in the charging cycle.
At maximum rate mine tops out at around 5200 ma using a 25 w brick. It varies between 1700- 5200 until it starts ramping down as the cell nears a full charge.
Nearing 90-100% it may be 800 ma or lower.

blackhawk said:
If the temperature is the same than it's not fast charging. Fast charging generates much more heat however even while it's enable the charge rates vary due to temperature, charge state and battery condition.
For instance between 80-100% the charge rates will be about the same. This may start as low as at 70% or even lower if the charging parameters aren't optimum.
The easiest way to tell is with an app like Accubattery. Put it on the charge page then use the power button to turn off the screen. Start charging. You have about a second if you turn the screen on to see the screen off charging milliamp figure. The charging log also tells what was happening but not when it happened in the charging cycle.
At maximum rate mine tops out at around 5200 ma using a 25 w brick. It varies between 1700- 5200 until it starts ramping down as the cell nears a full charge.
Nearing 90-100% it may be 800 ma or lower.
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But 45 degrees Celsius is not normal for a new device dont you think? I mean if it was 65W charging I'd say maybe it can get a little toasty but for 33W I'm sceptical.

TweaknFreak said:
But 45 degrees Celsius is not normal for a new device dont you think? I mean if it was 65W charging I'd say maybe it can get a little toasty but for 33W I'm sceptical.
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If that's the battery temp, it's high. The CPU can easily run beyond that though.
If the whole phone feels hot you got issues.

blackhawk said:
If that's the battery temp, it's high. The CPU can easily run beyond that though.
If the whole phone feels hot you got issues.
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It's generally the back portion of the phone specially the part below the camera module. I'm getting the device replaced tomorrow. Let's see what happens

Question Charging issue due to phone temp?

People keep saying that their chargers are not working. I noticed via AccuBattery that once my phone exceeds 100-104 F, that the phone stops charging until the phone cools down. I don't think this is a power brick/cable issue, I think this is a thermal management issue.

It's done to try and protect the battery from unnecessary stress and possible damage.
Optimum Li charging temp range is 82-99F
A start temp of 85F is better.
Never attempt to charge below 40F
Avoid starting charge below 72F
Fast charging will likely not engage if temperature is too low (around 71-50F or less).
Charging will disengage if the battery gets too hot about >103F.
Fast charging may disengage at 100F and will start ramping down around 80% and ramp down even more as it approaches 100%