No!
The battery usage only shows what percentage of total APP drain is in the past few minutes....
Say APPS are using a total of 10% of your battery.
Of this it shows swiftkey using 60-70% because it was the latest and most used app..so in reality it's used 0.06% battery total drain over the past five minutes.
On any android device there are three main drains...
Cell standby service (keeping in touch with the towers)
Display (brighter drains faster)
CPU
These three things are over half of your total consumption.
Wanna test this theory?
Take two identical phones, one that is in service, one that isn't.
Set the CPU on the in service one at stock, brightness at 100 and don't mess with network settings.
On the disconnected device set CPU to 1/2 and brightness at auto or 50%.
Delete the network interface application (will put name up later) to disable antennas. You can hit airplane mode but this is more accurate.
Leave both phones alone for a few hours a d check the battery level and stats.
Leave them alone and check back ina couple more hours...
Go scientific process!
