Since then it seems my battery had been draining much faster than usual.
I installed better battery stats, and at the time it appeared to me to be a game my son and I played often (Arc Redux) which left an orphaned media server process and caused the drain.
I installed m-kernel and did the suggested trickster tweaks. This brought some new life into my tablet, but the screen on time was still extremely low, like 48 minutes of screen before I had to charge. Online game or not, wifi and sync on or not. Something was messed up.
But before I could figure it out completely, my son messed my tablet again. He pulled the charging cable out by the cord not by the thick part on the end of the plug, and this was an older cord too, a little jenky. And I mean he pulled it out. I didn't see directly what happened but the end of the usb cord was split open and the micro part of it was "missing." Later my son "found" the micro end. I had to threaten him with never using my tablet again before he admitted he was the one that pulled it out, quick and fast, by yanking on the cord and not by carefully pulling it out by the thick end.
But now... my tablet was not booting past the PA splash screen. Luckily I could get to TWRP. Dirty flash didn't fix the bootloop. I couldn't do a NAND, nor could I backup to my PC over ADB, even though my PC saw the tablet, the backups were 0bytes. So I am pretty sure by him pulling the cord out like that it had to have shorted and corrupted my memory.
I ended up needing to do a fresh clean install, and this time I went with SlimKat. I also had to take the back cover off the tablet and bend the usb charging port back in, it was split open a little and no cable would fit snugly in there.
Fresh flash well and my tablet was working again.
But the battery life was/is still atrocious. Can't get much more than an hour of screen time. Regardless of if I am playing an online game, an offline game, reading an e-book or whatever. Something was still wrong, and on a clean install.
And even more curious, it was now reporting what appear to be random battery percentages. Meaning it will go from 75% to 50% and back, randomly. I installed better battery stats, disable critical shutdown (x-posed), trickster mod (and m-kernel a67) and some others I cannot remember off the top of my head. Greenify pro.
I "fully" charged it overnight 2 nights ago. My plan was to let it drain on standby (wifi and sync off) with minimal use until it died. And I was peeking, periodically, to see if anything strange was happening.
And I came across this....
Does anyone know if I just need to fully charge it and then let it completely discharge with no safe shutdown a couple of times to calibrate the battery correctly? Or is it worse, is it more likely that my battery is going bad and needs to be replaced?