Here is logs from MTKlogger, stock firmware 20171011, just after resetting to defaults

Also, I found some more info in kernel_log, what is absent in normal phones:
[UART]CANNOT GET UART[0] SLEEP ACK

It appears frequently.

blackview_admin wrote:

Can anyone send your problem phone to us to study this bug? We will pay you the shipping fee and will send you back when it be repaired.

Smartphone on the way to the seller, there are two common problems: 1. spontaneous reboot, 2. the battery consumption of 2% per hour due to lack of sleep. The smartphone is without resetting to factory settings, with all the saved settings and logs. Data on the seller and the track number of the parcel in personal correspondence. I would like not only compensation for the shipment, but the replacement smartphone new, without defects.

Hello:
I have the same problem, my BV8000 has a mt6757cd (P25) CPU, and four of their cores seem to be at "full throttle" (2392Mhz) always.
Tonight, without any use, the phone loosed 21% of battery in 7 hours.

this is my test hope it can be helpful, i have lost a 3% in about 10 hours

[quote="war_horse"]this is my test hope it can be helpful, i have lost a 3% in about 10 hours

Hello , i have the same problem, what did you do exactly ?

Thank you.

Durant fatih wrote:

war_horse wrote:

this is my test hope it can be helpful, i have lost a 3% in about 10 hours

Hello , i have the same problem, what did you do exactly ?

Thank you.

actually nothing special, cause i have never notice this problem, so i have test as said in the post, reboot the phone with all app closed, 3g and wifi off and screen locked and put it on the desk, this morning it had lost only a 3% in 10 hours, and the alarm clock had work despite the deep sleep of the phone. I give you my configuration, maybe this made the phone work good, first of all i have the latest firmware 20171011, then i have "intelligent power saving standby" ON, i think that is a must to give to our phone the deep sleep needed, then i have configured battery optimization as suggested by admin in the post for the bluetooth issue, so i have all set on "optimized" and i have unoptimized only these: bluetooth MIDI service, BT Tool, Bluetooth sharing(i don't know how is translate in english cause i have italian menu), call management (translation by me), Memory phone/messagges (translation by me) and Phone services, then to this list i have add whatsapp and another couple of app that i use for work and spotify to listen music, if you have problem to find the app to don't optimize then i can upload screenshots too, but you can easily find it inside this post

http://bbs.blackview.hk/viewtopic.php?f=191&t=333190

Thank you war_horse,
your configuration doesn't solve the problem for my mobile...Happy to see you do not have this problem.

the only setting i miss to say but i think you have already tried, is that the phone battery is set on "balanced mode" not on "performance"

yes, already on balanced.

Also encountered a battery discharge of more than 3 percent per hour in sleep mode, all your recommendations were performed on all available firmware, spontaneous downloads were not observed. Dump BBS I apply.