I really like my S7 Edge. However as a direct result of installing the Oreo update I have significant battery drain. The drain is attributable to cell standby which sometimes reaches over 50% of battery use. It definitely did not do this on Nougat, ever.
I have not added any apps to cause this problem and would really like a suggestion about what to do. I can't believe Safe Mode will have any effect as this has happened as a result of the upgrade, not rogue apps. I am not keen to do a factory reset either as I can't see the benefit. I have cleared the cache, removed some apps, restarted etc, turned off any battery hungry options in settings but to no avail.
If anybody could help me I would be very grateful. I believe it is a bug in Oreo or Samsung's altered version of Oreo but cannot prove either. I can't think what to do apart from find out how to downgrade back to Nougat, which I don't want to do.
Just a brief update: Our software teams are investigating this issue, but determining an exact cause has proven to be more challenging than expected. They're continuing to look into this until they find a cause and a solution for you - and we'll keep you posted on any news.
In the meantime, please do keep submitting your experiences here and log files via error reports through the Members app; as well as keeping your phone's software and apps updated to the latest versions.
Well as you may have read in the previous pages, it seems it comes from the modem firmware, people flashing their modem with the latest EREO firmware from HK & Taiwan (only flashing the modem, not the other parts) seems to have seen their battery life increase quite well.
With EREO modem flashed on my phone (without BL) I can confirm that "cell standby" is not hanging in the top of battery statistics anymore, but I CAN NOT confirm BETTER battery life at all!
Today's example: ~13h after charging to 100% with ~4h SOT. Atm I have 6% battery left.
Battery life is very unpredictable even with EREO.
I'm agree with other member of this thread (and also with @AntS who said that Samsung realised that problem is much complicated than simple modem bag) that even the cell standby is not anymore "causing" battery drainage according to battery statistics, something is draining the battery instead of it or drainage is splitting to few application in statistics.
my samsung is model samsung s7 G930FD (no edge), modem CP_G930FXXU2EREO_CP9801855_CL13630734_QB18329617_REV00_user_low_ship.tar
in page 17 work with this cell G930FD? Problem cellstandby issue with this modem?
Confirm this by searching info from internet, but I have read somewhere that ROM files for G930F are compatible with G930FD (only difference in these models is amount of SIM slots; there is same radio (only one module) in both models).
I flashed the bootloader and modem from earlier in this thread (EREO) and this fixed the cell standby issue, but I had similar battery life overall due to Google play services battery drain.
After initial positive impression I have the same experience in my case. Yes, battery stats looks different now and Cell standby is no more major driver. But the bug with battery drain is still here - it can hit after 10h after restart or even few days but then I have discharge rate around 2.5%/h with screen off and this happens only at LTE/4G. And the battery stats now shows emphasis of Android system and Google Play services. Of course I want to test full firmware but this is it by now.
I've made an experiment using BetterBatteryStats (great app btw!) and created a dump files of 2 cases - 1 hour of good sleep (~0.3%/h discharge rate) and 1h of bad sleep (~2.5%/h) and then comparing them side by side.
What I've found? Two dumps share almost the same deep sleep, awake and doze times, same CPU states, very close apps wakelocks, network usage and alarms. But in Kernel wakelocks there are 2 very distinct things:
ssp_wake_lock: 51 in bad sleep vs 15 in good sleep
ssp_comm_wake_lock: 234 in bad sleep vs 55 in good sleep
I think these are linked to modem and modem itself is draining battery so I can't see difference in awake and CPU states numbers.
@AntS, if this is appropriate, could you please add this short report to our case at software team? Because my message to Samsung Members is still unanswered and I don't think they are listening us. We (users) want to give feedback and logs but in reality support just ended with advice to make Factory Reset and go to service center. Or silence at all.
Also in processes tab I have 2 rather big differences, but this may be due to restart:
firstname.lastname@example.org: Sys: 38s vs Sys: 2s
spi1: Sys: 23s vs 2s
@Also I have to say that my friend has the same S7 @Exynos like me, no root, he uses OTA updates only, nothing magical. And he don't has this bug - nor Cell standby at Oreo nor any battery drain at sleep. The main difference between us - we use different mobile operators, so may be different equipment from the operator side make sense too.
Thank you for your contribution! I have the very same conclusion about battery drainage on Oreo as you. Only difference I didn't any researches as deeply as you did.
guys when samsung fix this bug with new update?
im contact to samsung abouy this bug but do not any good answer to me they think just i have this problem dont think all oreo updaters have this bug in use a data
I have exactly the same issue since oreo update. Significant battery drain. Phone feels warm. Very 40-50% battery usage by cell standby. I had wiped device cache from x recovery and it made a significant difference. Battery life improved. But after few days again having the same problem. Have wiped again. Let's see
This is just ridiculous, it's been a month and still they haven't fixed it. I have a samsung7 and is the worst phone I've ever had, I just bought it for the camera that is the only good thing of the phone. The warranty of my phone was 2 years and of course one month later after finnishing the battery was swallowed and had to replace it and pay for it. They are just scammers releasing a new phone every 10 months and crashing old models to buy the new ones.