My battery life recently has been really bad (28% in 35 minutes) on my ZTE Axon 7 with android oreo 8.1. I checked the battery usage data and it says that mobile network standby is using most of my battery yet i dont have a carrier. Any help? The phone is rooted if that helps. 
Feb 12, 2019, 11:29:14 AM via Website
Feb 12, 2019 11:29:14 AM via Website
Look like your phone is constantly seeking a mobile signal, and it will keep doing this untill it finds one!
And that 30% for apps is being used by apps running in the background!
Question: when you are done using a app, do you go to your active apps and turn them off?
If you don't, you should!
When you are not using this phone for long periods , do you leave it powered up or do you shut off?
Leaving it turned on even though it is in sleep mode will continue to use your battery charge. That would explain the 21% in systems usage.
— modified on Feb 12, 2019, 11:43:25 AM