Same problem , I also noticed I even while reducing the number of installed applications .
soon as I can I will reply your test with screeshot to 7 hours away so check if you depend on applications or is it just drain system .. .
Bios version that you have installed ? Serial 605xxx or?
I have a same problem. My Hi8Pro is 2016 may version. The barttey is drain in 7-8 hour a 48%. And this consumption is causing all of the Android system. It shows the screenshots. (Sorry I can't attach a screenshot, but similar as others.)
What can I do with this?
The Chuwi going to do something about this?