What is the root cause of famous iPhone 4s battery draining issue?

Question

Even with latest iOS 5.0.1 some 4s users do encounter huge battery drains (1-2%/minute) even when they are doing nothing with the phone.

Is it a hardware or a software issue? Should I get a refund?

Update: The phone was bought 3 days ago from Apple Store in London, UK.

Last night when the phone battery went to 10% the phone just shut down automatically, like other were doing when the battery was reaching 2%.

Also, I observed that the percent of battery discharge was not linear, meaning that sometimes I observed the batter level going down with 5-8% at a time (while using the Phone). If I remember well from the other iPhones I had, the battery discharge in percentage should be smooth.

Answer 1

If it's convenient, get a Genius Bar appointment and take it to an Apple store. I have heard that further software updates to correct battery drain problems will eventually be released. However, you have every right to be unsatisfied with the product in the condition it is in right now.

Answer 2

If you are losing 1-2% of battery charge every minute while in standby you should bring the device to the apple store, or wherever you bought it.
The battery might just be broken.

The battery issues that some people had (or still have) with their iPhone4S are reported as a battery loss of 10 to 15 percent an hour.
With a rate of 1-2% per minute your battery loses it's charge 4 to 8 times faster.

Answer 3

The cause of batteries draining is physics and chemistry.

CPU use drains the battery, so all you have to do is figure why the CPU won't sleep and you will have weeks of standby life.

I had an iPhone 4 last in standby for over 5 weeks (on a bet) and the battery in that phone is well over 18 months old at this point.

Here is the low battery log showing how long one charge of the battery lasted when you isolate the device and don't run apps on the CPU.

Incident Identifier: 32B64787-774B-44E2-9362-55E0DFA34419
CrashReporter Key:   f51c8deeb5a5044afeb4c9a6b09528b7e38b0fa1
Date:                2013-03-13 00:52:15 -0500
OS Version:          iPhone OS 6.0.1 (10A523)

MobileMail: com.apple.persistentconnection[MobileMail,95,MailAutoFetch-connectionmanager(0x1e57e290)]   NoIdleSleepAssertion == 255, held for 00:00:00
dataaccessd: com.apple.persistentconnection[dataaccessd,79,6E6ACD65-0112-4B16-8439-90B5335A8511-connectionman...]   NoIdleSleepAssertion == 255, held for 00:00:00
dataaccessd: com.apple.persistentconnection[dataaccessd,79,3721C174-0131-433C-A9C4-72A7AD586BDF-connectionman...]   NoIdleSleepAssertion == 255, held for 00:00:00
dataaccessd: com.apple.persistentconnection[dataaccessd,79,6E6ACD65-0112-4B16-8439-90B5335A8511-connectionman...]   NoIdleSleepAssertion == 255, held for 00:00:00
dataaccessd: com.apple.persistentconnection[dataaccessd,79,3721C174-0131-433C-A9C4-72A7AD586BDF-connectionman...]   NoIdleSleepAssertion == 255, held for 00:00:00
dataaccessd: com.apple.persistentconnection[dataaccessd,79,3721C174-0131-433C-A9C4-72A7AD586BDF-connectionman...]   NoIdleSleepAssertion == 255, held for 00:00:00
dataaccessd: com.apple.persistentconnection[dataaccessd,79,88C57836-D9E4-4B38-B195-A357D3D1C2DB-connectionman...]   NoIdleSleepAssertion == 255, held for 00:00:00
dataaccessd: com.apple.persistentconnection[dataaccessd,79,88C57836-D9E4-4B38-B195-A357D3D1C2DB-connectionman...]   NoIdleSleepAssertion == 255, held for 00:00:00

Hardware Model: N90AP
Awake Time: 13:25:04 (48304)
Standby Time: 842:08:47 (3031727)
Partial Charge: 0
Capacity: 1
Voltage: 3649 mV