Total noob here as far as doing anything special with my GT-N7000 running 4.1.2. It has been running JB for a while without problems but after an external SD got corrupted about a month ago, the battery is draining horribly. Right now phone is off because both batteries on hand went down to 3% after a few hours. I have original battery plus 2 new OEM ones, so unless the new ones are defective, it should not be the battery itself that is the problem.
After the SD card got corrupted (spontaneously unmounted one day and then got progressively worse despite re-formatting), I got a replacement card. I did a factory reset and moved back only those photos that I checked showed up okay in Windows photo viewer. Also, after I did my factory reset, I did not use a backup to restore, I manually downloaded the apps I use again and re-input, manually, all my settings and data. Other than the photos (about 150 jpg) I also have maps for offline gps (GPS navigation & maps by skobbler) on the card, nothing else that I put on the card.
I keep GPS off unless I am actively using it, same with wifi and bluetooth and I don't have 4G. I disabled many apps I don't use like live wallpapers, Google Play books, etc. I have disabled all automatic syncing & location services. I keep background processes limit at 3. I have power saving setting on.
Still, my battery drains horrifically, even when plugged into an outlet or my USB port & showing charging. It drains especially when I am downloading apps, for example, downloading maps for offline GPS took the battery from 88% to 12% in less than 1 hour (and no, my phone did NOT get hot).
I searched through many discussions lists about battery drain. Some suggested it was a JB problem but I ran JB for many months before this problem occurred. Others suggested a corrupt file system, but this is a new external SD card, and I reformatted it just in case, and I checked the files for corrupt images before moving them back. I am not sure how my internal SD would have become corrupted by the external SD but maybe that is the problem? How would I test for a corrupt filesystem on my internal SD?
I tried a battery doctor app to see if it was just the battery monitor that was defective, but the percentages agreed. I got so desperate that I rooted my phone to consider deleting some of those apps I had previously disabled. Rooting worked but I did have problems with CWM. (I assume this is not related since I only rooted a few days ago and the battery drain has been ongoing for a month.Using ROM Manager from the app store CWM would not work & I saw a note saying something about Samsung owners having to have a compatible kernel first. I did not know how to check that so tried a different method to get CWM on the phone (booted into recovery and installed Philz Touch 5 from a zip file on my external SD card). That worked but there is a newer version and although I could get it to install, once it was installed, I could not boot regularly, only into recovery mode. So I reverted back to Philz Touch 5.)
Anyway, since I had root I got Titanium backup & did a backup. I also used Philz Touch 5 to wipe the phone (although not a complete wipe of all cache & such since I am a noob and don't understand Dalvik cache etc). After the wipe I did NOT restore from the backup. Once again I re-downloaded my apps and re-input my settings and data.
I tried looking at wakelocks although maybe I need more guidance on what I am looking for. Nothing stood out at least to me. I also looked at things that check CPU usage, but again, nothing stood out. I did not take screen dumps (if someone would give me explicit instructions on how to do that -- assume I am a moron -- I could re-install those apps and check).
I am not sure what to try next. Do I assume my new OEM batteries are duds & order some off Amazon (one brand was recommended in another forum)? Is there a way to test my internal SD to find corrupted filesystem? If so, then would I reformat the internal SD and would that solve the problem? Should I delete those apps I disabled in the past? Some I could not disable before (AllShare, TouchWiz) and maybe those are the problem. I did notice TouchWiz was high on CPU usage & have not the foggiest notion what it does but I could not disable it before root. Other options -- I could try a custom ROM I guess, but as I noted earlier, I was having trouble with the newest version of Philz Touch 6. So this frightens me.
I would appreciate any guidance and suggestions you might have. If you folks can solve my battery drain problem, I would thank you a thousand times (although I don't think that is actually allowed by the forum)