After a lot of thought about having my iPhone 4S be future proof, with enough growing room for the next two years, I decided to take my Verizon iPhone 32 GB model back and pay the extra for the 64 GB model yesterday. Unfortunately, it resulted in my first bad Apple Store experience, but this thread is not the time or place for that discussion (a quick note on that: The first employee lied to me about what I had to do to make the exchange and sent me away on a wild goose chase. The second employee gave me the classic smooth, enjoyable experience an hour and a half later after having to make several phone calls and spinning my wheels while following the total BS the first guy fed me - at least there was a happy ending).
On to the issue of not remaining charged while plugged in. I made sure to run the battery completely down on my new pone yesterday, so I could begin battery meter calibration. The phone was plugged into a wall charger at roughly 11:30 PM. At roughly 4 AM, I checked the phone and the battery had charged to 100%. At this point, the battery icon (upper-right corner) had the plug icon in it, rather than the bolt icon, indicating active charging had completed (unknown for how long). I left it plugged in and went back to sleep. I got up just before 8 AM and checked the phone again. It had dropped to 96% charge, while still plugged in. I removed the cable from the phone, and plugged it back in to achieve 100% charge several minutes later.
For me, that's two phones with the same exact charging pattern we've been discussing with concern here. This seems to indicate that it is by design (or perhaps design error), rather than a malfunction. In other words, it seems plausible that if this is a result of the phone's firmware coding, then it may be changed/corrected in a future update to maintain full charge (draw operational power from the cable power source rather than the battery while still plugged in).
A co-worker of mine also has an iPhone 4S (different guy than the previously mentioned iPhone 4 co-worker). I've spoken to him about the battery loosing charge while plugged in issue a few times. He is one of those people who charges frequently, not always waiting to reach 100% before unplugging. He did however, indicate that since I first spoke to him about the issue, he's been paying closer attention to his. He told me that he's observed his phone *maintaining* 100% charge, while being actively used on and off for durations of at least, if not longer than an hour. His is an AT&T iPhone 4S 64 GB.
If his observations are true, I wonder if there are slight firmware differences between phones of different carriers (aside from the obvious cell-tower communications chipset programming). If not differences in carrier firmware (that might affect charging and battery usage while charged), perhaps just differences in the firmware of phones produced in different batches.
Two differences that I quickly noticed in my 64 GB iPhone 4S from my 32 GB version were Siri's voice sounded different, and "Settings" menu navigation was noticeably slower on my 64 GB phone. Keep in mind I am very acutely aware of minute differences in load times, animation glitches, and other subtle things - my brain is just kind of hard-wired like that.
What is different about Siri's voice? In my 32 GB iPhone, she had more of a sharper sound, with more emphasis on the higher tones - kind of more crisp sounding. On my 64 GB iPhone, she's a little smoother sounding, slightly more robot-like, less distinct treble/upper-range tone emphasis. Which Siri voice sounded better is debatable, but the point here is that there *is* a noticeable difference and I picked up on it immediately. While looking for settings to adjust her voice, I didn't find any, BUT I did find that I now had a choice of 5 different language settings. I'm almost positive that wasn't there with my 32 GB iPhone 4S. BTW - I happen to like the sound of Australian Siri's voice the best, but can't use it as it doesn't recognize my own speech as well and does not work with location based services.
The point I'm making is that it seems there is indeed some kind of difference in this phone's firmware from my last one. I doubt the differences are hardware-based.
What does this mean? In context of the mysterious loosing charge while plugged in issue we're experiencing, while others *might* not be (and my co-worker has insisted he is not experiencing it), if there are indeed different firmware variations out there - that might explain why some people are reporting this issue and others are not.
Bad news for me, but potentially good news for everyone else (who may be following this thread), my brand spanking new iPhone 4S is showing signs of image sensor pixel glitches - mainly, what appears to be malfunctioning pixels in the image sensor (or processing there of). I noticed this while watching a short video I took on our 42" TV. It was not present in video shot with my previous 32 GB iPhone 4S. It's completely invisible on the iPhone screen (not enough image resolution to show single pixels), but noticeable on our 1080p 42" LCD TV. It's something most people might not even catch, but my eyes were immediately drawn to it. My wife commented "It's just a couple of dots - what's the big deal?" My comment - I paid way too much to just settle for a defective image sensor, especially when the camera and video capabilities of the phone were a huge deciding factor. Anyway, I'll soon be swapping my phone again (after researching the issue a bit more first), which will offer me a unique hands-on with a *third* iPhone to compare the loosing charge while plugged in issue with.
On a side note, between the BS "we can't help you" guy I had the mis-pleasure of dealing with at the Apple Store yesterday and my current image sensor issues, I deeply regret ever returning my 32 GB iPhone 4S for the 64 GB model. Now I'm spending more time just trying to make sure everything is 100% with my new, expensive device rather than simply **enjoying** it.