[HTC U11  ROMs, Kernels, Recoveries, & Other Develo] i5lee8bit:
As CharliesTheMan said already, thanks for all your testing. I've had this issue since going super clean install early this month (accidentally soft-bricked lol), but now that I think about it, it was probably happening even sooner since the 3.7.11 update, but I just never really noticed it (plus, I bricked about a week after 3.7.11 was released, and work lately has been requiring me to use a lot of my phone/flashlight/email/etc, so I wouldn't have noticed the drain as obviously).

I believe it does have something to do with the Dec security updates in the kernel, and that in no way is any fellow dev's fault. If anything maybe Google is to blame for releasing a patch in such a microsoft buggy fashion. For nearly the last month, I've been randomly searching Google Play Services battery drain, and finding lots of people with the issue. Seems to be after Nov or Dec security updates over multiple phones (including Pixels, Samsungs, others).

For me, GSAM and BBS was showing Google Play Services as anywhere from 60%-90% of the source of battery drainage. At one point, clearing data on CleanSlate Companion app worked, but the problem came back a few days later. At some point in my searching all over, I found that reddit user "junkimchi" mentioned that this scenario always replicated the drain for him: Phone on charger while wifi is on. I then noticed the same exact scenario was true for myself, to my surprise.

Quote from user junkimchi: "My drain happens precisely when I plug my phone into the charger and on wifi. I know when its happening when the phone gets unreasonably hot and this starts right when I plug it into the charger. Then even when I take it off play services maintains the drain and the phone stays warmer than usual."

https://www.reddit.com/r/GooglePixel/comments/7duwt4/psa_google_play_services_battery_drain_is_real/

So for the last week, when I really needed my phone to last a while, I would turn off wifi and the drain would go back to normal-ish.

Funny enough though, and thanks to you, back on 3.7.10, I'm down to 0.6% drain per hour while phone is sleeping, I believe also because I installed the magisk module Enable Doze for GMS while trying to work out the drain issues (this module allow google play services to be battery optimized, which is normally not an option). On 3.7.11, phone literally would never go into deep sleep. Literally 0 seconds. Even more odd, I believe it got worse after the clean install, but again it's hard to say cause I bricked so shortly after 3.7.11 was released.

With even other people across multiple devices, different makes, models, etc. experiencing battery drain issues since the late 2017 android security patches, I very much believe that downgrading to 3.7.10 should solve the drain issues for lots of users, if it pertains to what we're describing with Google Play Services as the culprit / no deep sleep / etc. The issue seems to be buried somewhere in the update, and even tbalden's changelog notes the only difference going from 3.7.10 to 3.7.11 is "December security patches".

If it's not happening to you, consider yourself lucky. But otherwise, I would be curious if other people with the issue can replicate the scenario by having wifi on while charging at some point (again, as mentioned by reddit user junkimchi). I was also able to make the battery behave at one point by turning off location, but then it came back a day later even though I left it off. But the wifi/charger combination caused it to happen for me every time!

Sorry for not getting back sooner tbalden, I know we talked about this several pages back, but my 60 hour work weeks lately have been tough! ;)

Again, thanks for your testing cjrivera04, you've saved me a whole lot of headache!! My battery has gone back to amazing since reading your posts yesterday.