This happens on my iPhone and everyone else's that I know.

Literally fluctuates between 40%, 1%, 31%, off and don't get me started on how it changes when it gets cold outside.

If you've got a 6s, you might be eligible for a replacement:

https://www.apple.com/uk/support/iphone6s-unexpectedshutdown...

I'm pretty sure my phone is affected, but according to that page:

    To prepare your iPhone 6s for the battery replacement process, please follow the steps below:

    Back up your data to iTunes or iCloud.
    Turn off Find my iPhone
    Erase data and settings in Settings > General > Reset > Erase all Content and Settings

Just to replace a battery??

They swap out the entire phone, and send the old one out to be refurbed and sold.

Not anymore, at least the NYC stores don't. They take your phone in and give it back to you in a couple of hours(depending on how busy they are). That's how they did it when I had mine replaced last week. The 5th Ave store didn't have any batteries in stock so I had to either wait a few days or go to a different store that had them.

You should never send a phone with your personal data out in the wild. If an Apple Genius is going to take your phone to the back of the Apple store and out of your sight, back it up and restore it to factory settings.

They might be sending you a refurbished phone instead of replacing the one in your existing phone

It's always prudent to backup your data if your device leaves your possession. What if FedEx loses the package or it's stolen off the truck?

Well, in all fairness with regards to cold, this is going to happen with batteries - it's just their nature. When it's -20ºC out, my old iPhone 4s can only be out for so long before the already depleted battery just dies off.

But this is just the nature of batteries.

I've had a 4, 5, 6, and 7 and I've never had this happen once. Your comment seems more like a "LOOK IPHONE DOES IT TOO" than anything meaningful.

My 6 has started doing this just after its 2 year anniversary. I bet it has something to do with battery age as well

This can be "fixed" by resetting the battery data on the phone and then letting it completely discharge before charging. I've had it work myself several times (I own two of every model iOS device for app testing purposes).

Exactly the same for my 2-year old 6.

My 5s does it if I don't recharge it fully.

iPhone 6s seems to have this particular problem

If you have an iPhone 6S with this problem you can get it replaced: https://www.apple.com/support/iphone6s-unexpectedshutdown/

Yes. I deal with this.

It's called an anecdote. I think that's useful in this situation.

My iphone 5 does it. Tends to be around the 20% mark.

Yep, my 6S had a goosed battery, walked into the Apple Store and 15min later I had a new phone with a predictable battery (and a headphone jack, happy times)

I am one of the unfortunate owners of a Nexus 6P whose device was abrutely shutting down at random occasions. The phone would shut down when battery level usually was below 60% and I was out walking. At first I though it had something to do with it being cold outside (I live in Sweden) but later I proved that was not it. Phone itself has not been tampered with (running official Android, 7.1.1 OTA) and is in near mint condition with protective case used.

Anyways, I did what most people do not do and unlocked bootloader, installed TWRP and Pure Nexus Project 7.1.1 ROM and am happy to report that issue is now completely gone (I did stress-test it several times in below zero temperatures) !

So, no - it does not seem to be a hardware issue.

My Galaxy Note 4 did the same thing. But this was after about a year of use. And hey, after replacing the battery it works fine again!

And as an aside, I dropped my Note 4 recently and broke the glass. I was thinking about the possibility of getting a new phone. But after looking at this season's options I'm heavily leaning toward just replacing the glass. One reason is that no top-of-the-line smartphone seems to have a replaceable battery to avoid these problems.

More generally, this season's phones are also cheap-looking and cheap-feeling. The Pixel feels like a $200 phone at best, with its cheap aluminum shell, fragile-feeling uncomfortable buttons, and ugly plastic/glass/whatever square on the back. I've been losing faith in Samsung's build quality (I've had some issues with my Note 4 and my previous Samsung phone, and the news about the exploding Note really turned me off the company). Even the latest iphone looks uglier than usual (that glossy bezel really doesn't do it for me, looks like a free phone you get when you sign up for a phone plan).

2016 is a really really bad year for smartphones. None of these machines seem like they're really worth their price. The next great phone is probably going to be one that doesn't feel like corners were cut.

Yes, batteries definitely need replacing after a year or so, maybe 2 if the original battery was very good quality. Don't go with the cheapest eBay batteries either; Monoprice seems to be good if you buy directly from them. I've had my phone for a long time, partly because of the bad phone options with diminishing key features recently (SD card, removable battery). I've replaced the battery every year, and I can get down to 1% battery. When it runs down faster and can't make it that low, it's time to replace the battery.

Now, why this happens in a brand new phone like the Pixel is another matter...

I routinely replace my smartphone battery after 1 year of use, occasionally a few months later. The brand of smartphone doesn't matter: after one year of daily recharging a battery has seen it's best days. The hardest part is finding an original battery, especially on Amazon.

I'm still using my Note 4 and have been putting off upgrading for no real reason. I was about to buy the Note 7 until they started blowing up, but now I'm probably going to wait until the S8 or Note 8 or some other flagship coming this Spring.

I'm kind of the same way.

I went from a Note 4 to a Note 5, and ended up dropping my Note 5 causing the screen/LCD to break and not turn on. It looks like it costs about $300-400 to replace everything after asking a couple of local places, because the parts for this are expensive/out of stock. You might want to see if it's the same thing for the Note 4.

At that price, I'd probably just want to buy a new one.. but as you said, there's not a lot of good smartphones out right now.

I'm using the Note 4 again for now, which is actually a refurb/replacement because the original one's screen died randomly one day (without dropping it this time.)

Same story with my Note 4 - it was shutting off at 30% too, but I bought some new Anker batteries a few weeks ago and battery life is back to being solid and reliable.

One thing that really bothers me about a lot of the new phones is the slippery glass backs. The Note 4 has a textured plastic back with quite a bit of grip to it. I tried a friend's Galaxy S6 and it nearly slid out of my hand!

I suppose a silicone case would fix that, but I like being able to use the Note 4 without a case and not have to worry that it will slip away.

In my experience Samsung phone repair service is pretty good. They'll fix most faults for $75 and ship it back in a few days.

I had this on a Moto X after just over 15 months of use. I think it was only a slightly degraded battery lifetime at that point. Likewise, I'm guessing this has something to do with battery measurement as much as anything else.

Same here. Moto X 2nd Gen. Likes to turn off around 25-30% at times. Sometimes it seems that if I keep it powered off and charge it over night then turn it on (I often will just plug it in once it turns off and then power it on while it charges) it seems to sometimes then get down closer to 5% before power down. I too suspect it has to do with battery measurement.

> some Pixel devices are affected by the same infamous shutdown bug that plagued the Nexus 6P

I've been running 6.0.1 on my 6P for a while now. I hear so many people complaining about battery life after updating. Battery life and reliably is the most important feature to me. I haven't had the 30% battery issue and my battery life is great.

Same here. Originally, it would get to 5% then shut down, but it's gotten progressively worse. The highest I've had it shut down at now is ~20%. My first guess was that it's an issue of battery degradation not being properly accounted for, but the news about (new) Pixels suffering from the same problem makes it seem like that's unlikely. Hopefully this issue is resolved via an update, because I'd feel somewhat guilty recommending the Pixel to people weary of Samsung phones only to have major issues arise.

I'm in the same situation! It seems to be triggered by temperature change, but not sure.

My Nexus 6 did this quite often, as does my wife's HTC One M8. It definitely could be an Android issue, but I think it would have to be a particularly egregious and obvious mistake.

If it is software, I'd strongly suspect something at kernel level, since quite a few times in my experience, the shutdown is too quick for a safe shutdown. Userspace seems to get a notification that battery is low because it usually gives the "shutting down" alert, but then just shuts off in a suspiciously short amount of time.

I'd be more likely to think it's probably something in the battery/power stack that's not managing or reporting the power well. Discharge/voltage curves are not at all linear, [1] [2], so it's logical that issues with immediately available voltage might start to affect the device around the 30% level. Additionally, as another commenter has mentioned, the discharge curve is dependent upon temperature [3], so a sudden drop in ambient temperature will eventually have a direct effect on the reported voltage.

I'm not exactly sure what kind of metrics are commonly used for reporting battery percentage, but I am about to read a few (okay, maybe half of one) Arxiv papers that came up in a search. [4] Presumably, it's strongly based on some voltage modeling and I can imagine that would have a hard time coping with external factors beyond its measurement capacity, like ambient temperature drops. I don't suppose a user would be happy to see their reported battery percentage drop like a rock immediately upon stepping outside.

I really don't know where I was going with all that, except I guess to say that my gut says Battery "percentage" is a bit more an art than a science. That is to say, there are psychological reasons not to report based on voltage directly (it may go up if you step into a warmer room; "Wat?"), and I can imagine any metric is going to have its strengths and weaknesses, because you really can't account as much for user behavior that changes important physical conditions of the battery.

[1] http://www.powerstream.com/AA-tests.htm

[2] http://www.ibt-power.com/Battery_packs/Li_Ion/Lithium_ion_te...

[3] http://www.ibt-power.com/Battery_packs/Li_Ion/Li_Ion_DiscTGp...

[4] https://www.google.com/search?q=battery%20percent%20site%3Aa...