iPhone 5 battery drops to 20% from around 40% suddenly

This same thing is happening to me. I've only had my iPhone 5s for seven months and yet the battery is wacked now. Very frustrating, Apple! I don't like having a full battery that drops to 45% after a 15 minute walk to work in the cold with my phone in my pocket, not being used. This is a ridiculous problem that needs to be fixed, please.

I have this same issue. Once my iPone 5 get's around 30-40% my phone battery dies quickly. I might try the above suggestion that you turn off battery percentage and see if that helps. I was planning on trying to reboot as new and see if that helps but reading ither posts this seems futile. I really like the iPhone and really want to upgrade this year to the new phone but will admit these battery issues are really starting to annoy me and I have given thought to the new Galaxy. Someone quickly talk me off the ledge! HA!

I had the almost same issue as you do. For my issue, the problem was caused by nothing but by the battery itself which was over its useful life cycle. The battery status can be easily known by contacting Apple and submitting them your device diagnostic files. Luckily, I have apple care protection on my iPhone 5 so my carrier replaced my iPhone 5 with another phone. Now, I am happy with my replaced iPhone 5. No more annoying battery problem.

I've had a few cell phones in the past, and I was taught, and still to this day, make sure the battery is fully dead before charging it, because I was told it makes the battery last longer. I'm not new to the iPhone family. I had an iPhone 4 for two and a half years, and had no issues with the battery. I lost my phone last June, and the first week of July I purchased my iPhone 5. It worked perfectly fine up until January of this year. We had a major cold snap where I live, and one day during it my phone battery drained pretty quickly. I told a few friends about this and they said it's just the cold weather, so I didn't think anything of it. Come February, I was sitting at home trying to kill my battery before charging it. It was down to 19%, then just died. That has never happened before. I plugged it in right away (Usually it takes a few minutes to boot up) but the Apple logo popped up right away, and it was still at 19%, whereas when I plugged it in after it dying completly, it would say 4% or 5%. It was strange, but I thought it was just a fluke. Then, it happened again tonight. I was sitting in my car checking an app, when the battery was at 24%, and it just died. I got home about 15 minutes later and plugged it in, and once again the Apple logo came up right away, and the battery was still at 24%. A few seconds passed and I got a few text messages, and looked at the battery again and it was down to 9%. I don't know why it's doing this, but it's a real **** off. Does anyone have any suggestions?

If you're still within warranty, just send it back.

Alternatively you can get a battery replacement kit from ebay, I'll have to see if mine is still within warranty cause I have the exact same issue.

I was dealing with this problem for over 5 months, i tired everything suggested, in the end i replaced my battery with a new one and everything its working great, i belive it depends on how much you use your phone and how well you do the battery charging cycles that your battery life will last for morw or not. Point is.. sudden drops and phone having more than 10% pluggin it in means you need a new battery. Try finding the original 1440 Mah battery.. they are really cheap and perform as if the phone was brand new.

I'm not sure if I still have warrenty with Apple, because I didn't purchase Apple Care. I do, however, pay an extra $10.00 a month with my service provider for device protection, so I'm hoping that covers the battery. Thanks for your suggestions everyone!

Back on November 27th I also posted to this discussion that I was having the same problem as everyone else regarding spontaneous shutdowns of my iPhone 5 when it reached about 20% battery life. A couple days ago, when the phone shut down at 20% for the umteenth time I decided to do what had been suggested by someone in this discussion: do a Restore on the phone. I wanted to report back that this seems to have actually solved the problem! Not only does my phone not shut down at 20%, but the battery life seems greatly improved.

I started by doing a back-up of my iPhone to my computer, not to iCloud, and then immediately doing a Restore. In my case, the whole process took about 2 hours.

There were two other things that were happening with my battery that made me believe that this was a software or driver problem, and not necessarily the battery. I use a uNu battery case when I'm going to be away from a power source all day, and when I engaged the battery case to charge the phone, the phone's indicator would instantly jump 20-30% in capacity. That proved to me that there was still plenty of power in the phone but that it wasn't being reported properly by iOS. The second was that certain applications seemed to drain the battery very quickly, but there was no rhyme or reason as to why this would be true. With the Restore, both of these behaviors have disappeared.

I wouldn't go so far as to say this will work for everyone, only that it did for me and my iPhone 5. It is certainly worth a try before having to swap out the battery.

Just updated to 7.1 iOS and guess what - the dead battery that needed to be replaced after just over a year old suddenly is holding charge and not dropping like crazy every hour like before.

I am just not happy how apple has handled this issue.

I also have a older 4s with an older battery that never had an issue and needed a battery replacement as suggested by so many posters.

Didn't think I needed to hand apple another $100 for a battery that should at least last 2 years (contract period of US customers).

I think apple should have their default warranty to be at least 2 years on hardware and battery and not sucker people into buying AppleCare for more money

An update on my previous post. I updated to 7.1 a couple days ago and now I'm back to the same problem of having the phone reach 20% power and then suddenly shutting down. AARRGGHH!

I did try the backup/restore method I mentioned above but it didn't change anything.

Yeah I just updated the other day to 7.1 and backed up my phone, set the phone back to factory settings and restored it from backup and I still see the same issues. The only plus from doing all that is I seemed to gain 10 gigs of storage back from old deleted files that must have never fully cleared out. So not all a loss on my end. Just always carry my charger with me. Still....

False hope guys - sorry 7.1 didn't solve anything - phone still dies too soon and jumps in battery life both up and down are very erratic

Yesterday I bit the bullet, cried Uncle, and went to the Apple Store to have a Genius test the phone. Sure 'nuff, the battery tested bad–after only 379 cycles. I had a new battery installed (on my nickel) and I'm back to normal. I deliberately let the new battery run down to 3% and it behaved as I expected, with no unexpected shutoff.

Only 379 cycles for a battery? Really?

When will Apple be resolving thisssssss? I cannot not panic and go ninja when my phone is at 20% because I know that it'll drop to either 10% or less by the second. My phone now is with iOS 7.1.1 - when will this horror enddddsgfragrahth.

My "resolution" was to take it to a Genius and let him test the battery. In my case it was bad and in need of replacement. With a new battery this problem has disappeared for me.