Search though the G4 section of this forum and you'll find a few threads where I was dealing with battery issues with my phone. Being an engineer, I tried every test/experiment I could pull off to isolate the problem and was unable to come up with anything other than it being a hardware issue after several months of trial and error with settings, apps, usage, you name it.
Verizon Customer Service saw things my way and decided to replace my phone (under warranty, of course). The replacement phone seemed marginally better, but still suffered from similar problems as before. In particular, it would exhibit random instances of large battery drains (usually attributed to Android system-level processes by GSam battery monitor). Also, like the previous phone, it would occasionally get warm in my pocket without even being used (when it should be on standby). GSam monitor graphs seemed to show some correlation with cell signal, but not consistently and it was just as much influenced by screen-on time, making it difficult to tell who the real culprit was.
The Marshmallow update came along, with "Doze Mode" on board. This helped the standby battery life noticeably (like if I'd walk away from my phone at home and come back three hours later), but the times my phone actually went into "Doze" weren't often enough to really help with overall power consumption. I pretty much just lived with it. I got into the habit of charging my phone at work every afternoon just to be sure it wouldn't die before bedtime.
Fast forward to about a week ago... My phone succumbed to the dreaded G4 "Boot Loop" issue, which - according to the intarwebs - is the result of a manufacturing defect related to the "Big" processor cores which are used by the phone for all of the heavy lifting. Again, my phone was replaced under warranty. I loaded everything back onto the replacement device and went on with my life. I was not expecting to see any other differences, but I did...
To start with, under normal use, my average battery drain has dropped from ~6%/hr to ~3.5%/hr, when screen-on time is nearly identical to what it was with the previous phones. This is a real, measurable difference in battery life. Additionally, I have noticed that my screen-on time can go well over 2.0 hours and still have >50% batter life left. That was basically unheard of on my previous G4's. My usage, settings, apps and location are unchanged, but the phone is working more efficiently. I have also noted that the max temperature reported by GSam since getting the replacement phone as not exceeded ~95 degF. The old phones would regularly get to 104 degF and even higher at times. I don't even think I've seen the replacement reach 100 degF yet. I also have not had it get warm in my pocket like the others did.
So, how could this be? It got me to thinking... what if that "Big core" mfg defect that can lead to boot looping can also result in processor inefficiency up until the point when it fully fails (and creates the boot loop). Could it be that those "Big" cores were working harder than they needed to in order to compensate for date transfer errors internally, or perhaps a trace or circuit connection was not fully formed and lead to more resistance in the signal, generating more heat (lost power)?
I can't say for sure. You decide...
-SR-
Verizon Customer Service saw things my way and decided to replace my phone (under warranty, of course). The replacement phone seemed marginally better, but still suffered from similar problems as before. In particular, it would exhibit random instances of large battery drains (usually attributed to Android system-level processes by GSam battery monitor). Also, like the previous phone, it would occasionally get warm in my pocket without even being used (when it should be on standby). GSam monitor graphs seemed to show some correlation with cell signal, but not consistently and it was just as much influenced by screen-on time, making it difficult to tell who the real culprit was.
The Marshmallow update came along, with "Doze Mode" on board. This helped the standby battery life noticeably (like if I'd walk away from my phone at home and come back three hours later), but the times my phone actually went into "Doze" weren't often enough to really help with overall power consumption. I pretty much just lived with it. I got into the habit of charging my phone at work every afternoon just to be sure it wouldn't die before bedtime.
Fast forward to about a week ago... My phone succumbed to the dreaded G4 "Boot Loop" issue, which - according to the intarwebs - is the result of a manufacturing defect related to the "Big" processor cores which are used by the phone for all of the heavy lifting. Again, my phone was replaced under warranty. I loaded everything back onto the replacement device and went on with my life. I was not expecting to see any other differences, but I did...
To start with, under normal use, my average battery drain has dropped from ~6%/hr to ~3.5%/hr, when screen-on time is nearly identical to what it was with the previous phones. This is a real, measurable difference in battery life. Additionally, I have noticed that my screen-on time can go well over 2.0 hours and still have >50% batter life left. That was basically unheard of on my previous G4's. My usage, settings, apps and location are unchanged, but the phone is working more efficiently. I have also noted that the max temperature reported by GSam since getting the replacement phone as not exceeded ~95 degF. The old phones would regularly get to 104 degF and even higher at times. I don't even think I've seen the replacement reach 100 degF yet. I also have not had it get warm in my pocket like the others did.
So, how could this be? It got me to thinking... what if that "Big core" mfg defect that can lead to boot looping can also result in processor inefficiency up until the point when it fully fails (and creates the boot loop). Could it be that those "Big" cores were working harder than they needed to in order to compensate for date transfer errors internally, or perhaps a trace or circuit connection was not fully formed and lead to more resistance in the signal, generating more heat (lost power)?
I can't say for sure. You decide...
-SR-