[Galaxy S6 Q&A, Help & Troubleshooting] ImPain:
Dear all,

I am writing this post to hopefully get some help or directions regarding my issue, because I have already spent hours and hours looking on the internet trying fixes on my phone without anything working for me so far.. So I am getting a bit hopeless....

I recently got a Samsung Galaxy S6 (SM-920I model), and since the beginning i have been shocked by how CRAPPY the battery life was. To give you some ideas, my phone loses around 3-5% of battery per hour when idling and screen off, meaning I am not doing anything at all with my phone. Overnight, I lose about 15-20% battery with my phone on airplane mode, power saving, or whatever else you want, when it is not doing anything at all..

I know that my problem is a deep sleep problem, quite easy to identify i guess, so I have spent a lot of time reading and trying to fix it by myself but so far nothing worked.

To give you some background, after unpacking the phone I quickly upgraded Android from 5.0 to 5.1.1, so I cannot tell how it was working at 5.0. It is only after that I saw that a lot of people have issues on 5.1, but it is strange because just before having my S6, I was having a OnePlus One on 5.1 and I didn't have such battery problems and everything worked fine except turning off the "keep awake" setting option for GooglePlayServices.

What I can say though, is that since I upgraded I never had so much difficulties trying to fix a problem on any Android phone than before. Basically, since day 1, my phone never went a single time into deep sleep mode.

So far, to fix this, I tried all the following:

- Reflash the stock firmware (Samsung 5.1.1) --> many times, with full Cache/davik wipe and factory resets

- Root my phone using UniKernel

- Install custom ROM (I am running XtreStoLite version 2.2) + all kinds of wipe/factory reset

- Flash different kernel that are shipped with the ROM (there are 5 different ones if I remember)

- Use my phone with only stock apps (to see if the problem comes from one of my apps)

- Cold reboots

- The "DeepSleepFix" using the Android terminal as described here: http://zidroid.com/fix-battery-drain-and-deep-sleep-issue-on-galaxy-s6-and-s6-edge/

- And desperately, try to use my phone normally for now

Overall, I would say that my battery would last roughly 15 -20h in total with normal usage, not even heavy, which quite sucks..

I can show the no deep sleep issue to you with some screenshots (cf. below)

, I have tried many applications to try to find the root cause such as:

- WLD

- 3C CPU

- BetterBatteryStats

- GSAM

etc.

I am monitoring my phone closely for the past 1-2 weeks and so far I have never seen it being in deep sleep at all (at least more than 0.2 seconds in total..). Also, when I check on the default Battery menu of Android, after a full day I would usually see "Android OS" on top and using 20-30% of the battery at least.

The problem seems to boil down to a process called "LHD" in the kernel wakelock. This is keeping my phone awake 100% of the time, whether I am using the phone or if I am not. However, even with this info I tried to search online and I cannot find anything about "LHD", so I am really stuck right now.. Do anybody knows what it is and why it is a problem for me?

If any of you have a solution or can give me some guidelines to help me fix this issue, I would really appreciate any help. If you need more information from me also let me know.

Thank you for taking the time to read me,

Best regards.