I've been hit with what I'd like to believe is a bad battery, but I'm not completely sure.
If I leave my phone plugged in overnight, I'll have ~45-50% charged by morning. At this point, if I turn off the phone and remove the battery for about a minute, I will get a reading of ~85-90% charged after reseating the battery and booting the phone. Unfortunately, the higher charge reading doesn't seem to have any bearing on the battery's ability to power the device. After a couple of hours (with only a bit of use), the charge reading will drop down to ~25% or lower.
So... a bad battery? Maybe. Even though I haven't had the opportunity to use NFC, I think I'd like to keep that as an option.
Also, I don't know if I want to get a whopping huge extended battery (Eleventy-MILLION-maH!!). I'm not finding much on Amazon or ebay - am I just missing the right search terms, or is there a better place to look?
So, I contacted Samsung support & was told to 1) factory reset the GNex, and then, after a few hours of attempted charging & no noticeable difference in battery behavior, 2) contact Google support, as Samsung thinks it's a software problem.
My take-away: I'm hosed. Oh well. The phone still works and now I have three batteries. I'll just have to remember to always carry a spare.