yashsingh1/xdaforums huggingface dataset:
[Nexus 5 General] haskida:
did u use an USB extension cable with the LG charger? because i noticed on mine when i use an extension cable with the charger, the ampage i get on my phone is significantly lower than without one, monitored with battery stat widget.

the battery % even drops when i keep my screen on while charging with the extension cable.

if i use only the cable it came with, then everything is normal.

this is weird because with my old galaxy nexus and the samsung charger it came with, i could use the extension cable without slowing down the charge. it is probably due to the cheap quality of the LG charger... but im not complaining as galaxy nexus was a 600 dollar phone
[Nexus 5 General] Lucke:
same here.

yesterday, i charged from ~4% to full in 2.5 hours on the N4 Charging Orb. i'd consider that pretty fast for wireless
[Nexus 5 General] lalakersfan88:
pretty amazing, I forgot to charge my Nexus 5 overnight so it pretty much stayed stable at 20% overnight with data off, wifi off...just phone on.

So, I charged it this morning and in 2 hours it went from 20% to full.
[Nexus 5 General] Qbancelli:
Not only with the wall charger, it also charges fast with my Samsung S4 wireless charger.:good:
[Nexus 5 General] Caelrie:
I couldn't be happier with the battery behavior on this phone. It easily lasts me all day, and charges really really fast.
[Nexus 5 General] bblzd:
When it starts charging I notice 1% a minute but at some point it slows down. The GS4 quick charger is apparently even faster.
[Nexus 5 General] grizzlywan:
The Nexus 5 uses a Texas Instruments BQ24192 chip for battery charging and power path management, which does not work with Qualcomm Quick Charge. So whatever is making the charge speed this fast is not from Qualcomm's Quick Charge 2.0.
[Nexus 5 General] legendnexus:
mine takes around three hours too!! WTF??
[Nexus 5 General] rancur3p1c:
If I recall correctly one of the largest stressers on the battery leading to premature failure is thermal cycling, usually from high loads or charge rates. The expansion/contraction of the cell serves to slowly separate the anode/cathode from it.

There is also something else, chemically, that occurs in the cell when you put power through it, which over time wears it out, this is quantified in the lifecycle/number charge cycles.

Toyota got around this by keeping the batteries within a very specific voltage range, where this effect is reduced.

It was a couple years ago I looked into it and as soon as I reached the conclusion I ran with it and dropped the premises that lead to the conclusion. :D That's how my brain works!

I think 0.8C is absurdly high. On non-user-replaceable (well this one is, but still a pain) batteries I like to take every precaution. Slow, deep charges; and run it down till it dies at idle (with screen off) every several weeks to recalibrate the cells. I've yet to have any batteries need replacing or even lose any capacity. Well there was one that I managed to nuke the 15%-5% region of the cell by running my OGDroid at full brightness, playing music, navigating, loading a webpage, and overclocked to 1.2Ghz in my car in the sun on my dash on a 95 degree summer day but I don't count that.
[Nexus 5 General] jswede:
If you need empirical data, just test charge and discharge some batteries on a battery analyzer at different rates and you will see the difference in available capacity. I have done this many times for rechargeable cells used in high reliability applications. The difference is small, but noticeable.

Additionally, it's a known fact that faster charging creates more heat. Heat degrades the crystal structure of any rechargeable batteries in addition to wearing out the mechanical components of a battery (foil, separator, etc depending on the battery design). This is a well established and well understood fact.

With that said, battery charge control technology has made incredible improvements in the last 10 years. As a result, many of the rules of thumb for older chemistries (NiMH or NiCd) are not as relevant anymore. However, slow charges are still beneficial.
[Nexus 5 General] rancur3p1c:
have you done this on any Lithiums?

What % do you consider "small"?
[Nexus 5 General] jswede:
I've done it on lithiums. To me, small is about 5% difference.
[Nexus 5 General] tmagritte:
Nothing wrong with taking a very conservative approach if that suits you and should definitely give you the best chance of having no battery issues. But this doesn't answer the question of whether you would have had any serious battery issues if you weren't so careful. Even if faster charging does reduce the capacity and longevity of the battery, does the effect have a large enough magnitude to have a real impact on how you use the device. Because there are so many variables involved anecdotal accounts can't answer that question. You'd some kind of reasonably controlled experiment with a large enough sample size to establish statistical significance and reasonable estimate of effect size. I wouldn't be surprised if these experiments have been done but I suspect you'd have to delve into the technical literature. A simple Google search is going to be frustrating as there is also a lot of misinformation out there.

Assuming we take your stated facts as gospel, there's still the question of how much heat is necessary to have a significant impact on the battery. There's clearly a heat sensor on the battery as the phone is able to report battery temperature so presumably the charging logic can take this into account and drop the current as necessary to keep the battery within safe temperature range. I suspect there's some debate as to what a safe range is in relation to the speed of battery degradation so the manufacturer makes some decision as to an acceptable tradeoff between battery life and charging speed. So of course limiting the charging current externally will help tilt the balance towards battery life if this is a concern to you.

How many cycles does it take to cause a 5% decrease and how linear is the response to cycle number? If we're talking the equivalent of 5% every 1 or 2 years with a daily charge I wouldn't even worry about it. If we're talking every 3 months that's an issue...

Interesting conversation. Thanks guys.
[Nexus 5 General] psommerfeld:
I'd love to know what I'm doing "wrong"? Mine takes 6 hours to charge from 20% to 100%!

I'm using the wall charger that came with the phone??
[Nexus 5 General] jswede:
You're welcome to take my stated facts however you like. I have years of experience in reliability and process engineering where I was responsible for multiple battery cell chemistries and their applications in high reliability products (not consumer products). I've also worked directly with battery cell manufacturers, who have an extensive understanding of their cell performance and characteristics.

In regards to the number of cycles, it all depends on the quality of the battery. The deposition processes used to manufacture today's high capacity batteries are very touchy and require very good process controls to maintain a quality product. This is why a $5 battery off eBay typically only lasts a few months before it fails.

As far as estimating the impact of temperature, the Arrhenius relationship applies very well. Generally, an increase of 10 degrees Celsius will double the degradation rate. Similarly, a reduction of 10 degrees Celsius will half the degradation rate. This is not a 100% accurate or precise estimate, but it is the closest you will get without directly testing a cell. If you can find the activation energy as tested by the cell manufacturer, you can get a little closer on these estimates. You will not find this information for a phone battery without determining who produced the cells and referencing the technical data sheet for the raw cells.

IMHO, you should use only OEM chargers if you're concerned about cell damage. They will limit current to the specifications of the device manufacturer and ensure the battery charged within specifications.

Personally, I use whatever charger I want and always look for high current output chargers because I'm not a patient person. If I damage my battery over time, I'll just buy a new phone. Since I replace my phone at least yearly, I never have service life issues. If you're on a two year replacement cycle, you likely will have service life issues depending on how heavy of a user you are.
[Nexus 5 General] psommerfeld:
Great post, I like the detail (even though I snipped most of it).

Sooo ... who IS using the charger that shipped with the phone? Because I'm getting extremely slow charge time with it ... 7-8 before the battery is fully charged (I leave the phone on while charging). Just curious if they limit the charge on it. I guess I should look at the wattage on the wall wart, if it's written on it.
[Nexus 5 General] Sesamechicken:
I haven't really noticed
[Nexus 5 General] Mr. Sprinkles:
The charging chip in the phone is responsible for this. It limits input current to 1.2A at all times, so feel free to use whatever adapter you have on hand.
[Nexus 5 General] rancur3p1c:
happy it goes slow but 1.2A would be enough to charge it in 2-3 hours (2300mAh/1200mA = ~2hours)
[Nexus 5 General] Mr. Sprinkles:
I use it, my phone is able to draw 1A from it, no problem (never seen the phone draw more than that with any charger). To the people reporting slow charge speeds with the LG charger, it's quite possible you have a defective one. I've heard of chargers from other manufacturers which didn't have the data pins shorted inside. If this is the case with some of the LG chargers, it would tell the phone to only take 500mA, which would explain the long ass charging times.
[Nexus 5 General] bblzd:
Sounds about right to me. Less even since I've yet to charge from 0%. I will usually end the day at around 50% but charge anyways just in case. A wireless charger would probably do me good.

Default charger + extension cord.
[Nexus 5 General] EcPercy:
I didn't use an extension cable, although, I didn't use the original cable either as it was about 4" too short. I used a cable from my old HTC charger. My plan now is to get a dual qi charger since my gf has the N4 and I have N5. I think that will work out better than using the usb chargers.
[Nexus 5 General] uao:
for the first time in my life I have a pphone that makes it trhough the day, battery life is just great, great optimization for a 2300 battery! During the days of heavy usage I just need 30/40 min on a wall for some good extra juice.

I agree with the OP sentence, it charges really fast and thats the point, no matter if other devices are better or the same I own this one and will never wish to change a nexus for something that costs twice this awesome phone.
[Nexus 5 General] rcmc:
Having short charge time and short usable battery life feels like the phone is using a shallow depth of discharge to make the battery hold charge better in the long run. Would be interesting if someone can somehow measure how much electrical charge there actually is between the phone saying 0% and 100%. Hopefully this would mean I don't need to take it apart within the next 24 months for a new battery.
[Nexus 5 General] ExtremeAthlete:
You need to keep the question mark inside the quotes as in, "What am I doing wrong?" Also, try turning your phone off before you start charging it.
[Nexus 5 General] letmedanz:
My phone too seems to be on the wrong end of things..

5-6 hrs for a full charge using the packaged charger...

To top it, my battery lasts 5 hrs too...
[Nexus 5 General] MisterEff:
Mine did that the first night and after that it was perfect. Check gmail sync. I set mine to 30 days instead of all mail and it was better after that...or maybe that was a coincidence.
[Nexus 5 General] ExtremeAthlete:
YouTube Nexus 5 Save Battery

I turned off the following and got 1D 5H 23 M!!

-LTE to 3G, still really fast in my area avg 6mb/s.

-Location to Battery Saver

-Auto brightness to 10-20%

-Sound Vibrate when ringing to Off

-Language and keyboard input vibration to off

-Push email sync to one hour

-Hot Word detection off (press and hold home screen, settings, voice)

-NFC to Off

Good luck!
[Nexus 5 General] herosemblem:
I cannot figure how to edit gmail sync frequency. Thank you in advance for your help.
[Nexus 5 General] Chad_Petree:
Damn ! The nexus 5 is just loosely based on the g2 , I think the only thing they have in common is the snapdragon 800 and 2 GB of ram , the rest is totally different :/
[Nexus 5 General] NovaSlim:
After a 1D 15hr with 6 hr screen on time draining, my phone charged from 18% to 100% in sub 2 hours with the stock charger.
[Nexus 5 General] kippd:
Went from 45% to 98% in 50 minutes flat, so getting a tad better than 1%/minute.

I'm very happy with the speedy charge times for my N5
[Nexus 5 General] hmanxx:
I owned both nexus 4 and nexus 5. I am still using Nexus One 1.5A charger to charge Nexus 4 and Nexus 5.

Nexus 5 is definitely faster and close to the 1% per minute estimate.

Nexus One charging time is the fastest

Nexus S ,worst charging time, close to 3 hours

Galaxy Nexus, time vary with charger but better than Nexus S

Nexus 4, better than Galaxy Nexus

Nexus One-> Nexus 5-> Nexus 4->Galaxy Nexus-> Nexus S

Among all Nexus S also the least exciting Nexus Phone :D

I like nexus 5 charging time..I dont like to do extended charging time, usually in the morning...i just need to charge 20min to bring the battery up from 20% to 40% and off for work..I could not do the same for nexus 4.
[Nexus 5 General] Danub:
charging now and its only been like an hour but was at 9% and has reached 76%!! Very fast charging!

---------- Post added at 09:16 AM ---------- Previous post was at 09:01 AM ----------

I would like to save battery but disabling many things would make the Nexus 5 seem less worth what you paid for? Isn't the whole point of owning a phone like this to keep stuff like LTE on etc?
[Nexus 5 General] notbrodie:
I just disabled auto-sync and got 2 days standby with 3.5hrs screen time. the only thing that I sync is one rather unimportant Gmail account that I can manually refresh. this is with faux kernel

I'm now at 50% with 2.5 hrs screen time and an hour of streaming music (about half of it on mobile data). Franco kernel.

i have location set to high accuracy and am using lux auto - brightness. I've set the max brightness to 60% (which is plenty bright for Portland weather)

Sent from my Nexus 5
[Nexus 5 General] AndrasLOHF:
Wireless and ac charging are amazingly quick for me. USB charging on the other hand is absolutely abysmal. Even when trying to use kernels that force fast charge. If I am in any way using the phone or have DashClock Daydream on when USB charging the phone will not charge at all or will lose battery life. Tested it on 3 different computers,4 different cables, 6 different USB ports. Kernels with fast charge on my Evo LTE charged just as fast as AC using the same equipment and without fast charge would gain battery.
[Nexus 5 General] hotleadsingerguy:
Actually, all modern smartphones are the same. The Galaxy S4, HTC One, Note 3, iPhone iterations, etc... all charge at a quicker rate.

Most charge around 1% per minute (assuming the battery is 2,300-2,800mAh). Wireless charging is a little bit faster than half that (generally around 60%), but so convenient to make it worthwhile.
[Nexus 5 General] RIPPER03:
I have an older LG wall charger and can go from less than 20% to 100% in an hour...haven't unwrapped the ones in the box yet...

USB from my pc take forever tho.

Also,every charge has lasted more than a day and a half...hence...

Not sure what all the early battery complaints on the web were for.

Way better than my HTC One s which is now retired.
[Nexus 5 General] levesqu6:
I've been looking at the source for some of the kernels that claim to implement fast charge and I think they are missing a pin toggle that would allow the higher charge currents they load into the registers to be implemented. I hope the developers are able to take some time to look at this.

From page 21 of datasheet for bq24190

"Input Current Limit Detection

......

The bq24190 follows battery charging specification 1.2 (bc1.2) to detect input source through USB D+/D– lines.

The bq24192, bq24192I, bq24193 sets input current limit through PSEL and OTG pins.

After the input current limit detection is done, the host can write to REG00[2:0] to change the input current limit"
[Nexus 5 General] GunninZombiesdown:
Mathematically that makes sense.

Givens: 2300mAh battery, change in charge- 40%, charge time- .75 hrs, input rate- 1.2A

So 2300mAh*40%/.75hrs= 1226mAh= 1.23Ah.

Few factors to point out- 1) actual charge rate probably isn't 1.2A constant, the phone is using power while charging, and the battery will usually charge at a different rate as it gets filled (like from 90% to 100% may charge at .6A, but that's just an arbitrary number).

---------- Post added at 11:15 PM ---------- Previous post was at 11:01 PM ----------

Really? You can't say you didn't come here just to troll. Think I'm being a jerk? So GS4 charges at max rate of 1.5A taking a theoretical min time of 1.7 hours (2600mAh/1500mAh) and Nexus 5 is 1.9 hours OR 12 MINUTES. Thing is that according to http://xdaforums.com/showthread.php?t=2274321&highlight=charger the charge rate fluctuates between 1.2A and 1.5A. So using a median, 1.35A for GS4 is EXACTLY THE SAME TIME.

Go away troll, you're drunk.
[Nexus 5 General] mmmmBACON:
I did some tests today charging with different inputs and with my Qi charger, for the Wireless charging thread. http://xdaforums.com/showpost.php?p=48856141&postcount=18

I'll just copy over what I found.

So pretty much what you calculated and what I've recorded with the USB cord tests match up quite closely. Also, there's no reason to go beyond the 1.2A stock Nexus 5 charger. I'm assuming it's built in to limit the charge rate to around 1050mA as even using my 2A adapter, there was no increase in charge speed.
[Nexus 5 General] GunninZombiesdown:
That's really interesting- especially how you got odd rates from the usb 3.0 ports. Must be a software thing controlling the charge rate on the computer end. So I wonder if CurrentWidget deducts what the phone is using from what is coming in, or if the this charge rate was dependent on what level of charge the phone already had (like if it had a 70% charge and the max input rate was decreased?), and third how accurate CurrentWidget actually is. Don't get me wrong, as an engineer I love seeing this kind of stuff and it is on my main homescreen right next to the clock as it has been for months but really, just how accurate is it? Awesome work though man.

Edit: it's really cool to see that your work shows how efficient qi chargers are- baseline 1053mA (AC) max and 751mA (qi) is 71.3%. This is really cool to have some tangible numbers for what their efficiency because I've just been assuming an arbitrary 70%.
[Nexus 5 General] mmmmBACON:
Yeah I haven't figured out what is causing the USB port variations. All I'm going by for now is that they're less than peak, so I'm going to avoid it. 2A USB wall adapters are pretty cheap anyway, so might as well use that to get the best out of all the charging methods.

I'm not sure if CurrentWidget is 100% accurate, but save for tearing things apart and using a multimeter on contacts, it's the next best thing. It also seemed to be relatively consistent, so even if it may not be right on the ball, it's useful enough in testing variances in CurrentWidget readings haha.

I'm relatively confident the charge rate readings I was getting though were the max, and not limited by slow downs during the beginning and end of the charge cycle as I avoided taking readings beyond 70% and before 20%. They should represent an area where the charger is given full power to juice up the battery.

I was also just going by the ~70% average efficiency, because that's what all of the Qi chargers are advertising. At least we know (from my cheap Qi charger anyway) that they're not lying and it's hitting those numbers pretty much dead on.
[Nexus 5 General] markdapimp:
Charging seems slow for me

Anyone got any tips?

im on stock 100%
[Nexus 5 General] EarlZ:
When I tried my Galaxy Note 2 charger it gave 1600mAH to the phone now it barely charges at 1000
[Nexus 5 General] mmmmBACON:
Define slow? That's a pretty vague description.

Also, are you talking 0 - 100%?
[Nexus 5 General] markdapimp:
15- 100% taking like 2 ~ 3 hours
[Nexus 5 General] GunninZombiesdown:
It should take 2 hours, almost exactly. 2.3mA battery, 1.2mA charger
[Nexus 5 General] mmmmBACON:
2 - 3 hours is a pretty big difference from each other to use a ~ with! haha. That's an entire 60 minute difference. You need to be a little more precise than that dude.

If you're using the stock LG wall charger, it should take around 2 hours. If it's from 0% it will be a little longer than 2 hours because it charges a little bit slower at the beginning and end of the charge cycle, for safety reasons and to protect the battery.

That's as fast as it will go, you can't really boost the charging speed any further by using a higher Amp adapter or anything. The Nexus 5 seems to be set with a max speed level for charging.
[Nexus 5 General] markdapimp:
is there a difference with the stock LG ac adapter does it have some smart IC amperage/voltage control or something that communicates with the phone

my S3 charges for 5-30% very slow but at 50% it starts rapidly charging and you can tell by feeling the ac adapter it gets really warm, im just not seeing this with the nexus 5 atleast with the stock lg adapter
[Nexus 5 General] mmmmBACON:
No, it's not in the adapter, the controls that dictate the charge rate are built into the phone. The adapter just converts and supplies power. You don't have to use the stock LG adapter, you can use other 5V adapters. I use the stock LG 5V 1.2A adapter, and other 5V 2A adapters, and the highest charge rate stays the same.

As for the Samsung AC adapter getting warm and the LG not, I'm not familiar with the S3 or it's adapter, but I could guess that it might be just down to the LG adapter having a built in overhead perhaps, or even just a better build quality.
[Nexus 5 General] GunninZombiesdown:
Its probably just getting hot because of cheap metals used in the capacitors and resistors. Saving a cent or two to a company that sells literally millions of these things (chargers supplied with every phone) a year goes a long way so every corner will be cut.
[Nexus 5 General] _jordan_:
Quick charge 2.0 ftw.

Device charges like a monster.
[Nexus 5 General] Chad_Petree:
The Nexus 5 doesn't have quick charge 2.0 :'(
[Nexus 5 General] bblzd:
The more you're phone is doing while it charges the longer it will take. Try enabling Airplane mode when you need a quick charge. 0-50% shouldn't be longer then 30mins.
[Nexus 5 General] abdel12345:
Using my nexus 10 charger charges it even faster though im not sure if that's good or will it mess up the battery
[Nexus 5 General] GunninZombiesdown:
Wait, what? No it doesn't. Max input rate is 1.2A regardless of what charger you use. See this thread: http://xdaforums.com/showpost.php?p=48856141&postcount=18

But yeah, generally the slower the charge, the better for the battery.
[Nexus 5 General] deepthought_s:
I think the charging speed is awesome. Now waiting for my qi charger with automatic coil positioning. I wonder if my case makes it charging slower over qi
[Nexus 5 General] jwong.hhf:
Charge is fast indeed. But also the discharge.:crying:

It drains 10% in 3 hours with only wifi and cell phone signal on.
[Nexus 5 General] FuMMoD:
On idle? Check your wake locks cause on wifi and 4 bars of signal for me I get 1 percent loss after 8 hours of idle. My sync is off though.
[Nexus 5 General] drive7:
Well said. I'd like to hear what an electrical engineer has to say about this "fast charge=bad battery" stuff.
[Nexus 5 General] cgonzalez82:
If left to charge and not used it is very quick, and with some electronic background there's no truth in a fast charge being bad...