Using Google Services like Play Store saps my Battery like no tomorrow .... My WI FI also saps my Battery like crazy, and I have disale WI FI features like stop searching for new connection points ect ect.
My sister got the same phone as me yesterday, and her phone out performs mine with battery life. My phone will drain much faster if I just leave it on my desk with WI FI enabled, than she would while playing games on her phone with her WI FI enabled
I have found this information internally that might relate to your Wi-Fi issue.
You might experience that the battery usage for Wi-Fi® displayed in the Settings menu may show an incorrect value in the Xperia™ XA. This may happen after you turned off Wi-Fi®. This is a known issue and will be corrected in a coming software release. As a workaround, a restart will fix the issue.
Note! Software rollouts are a phased process – timings & availability may vary by market/carrier.
To view your battery consumption and estimated battery time
From your Home screen, tap the Application screen icon.
Find and tap Settings > Battery. An overview appears showing battery percentage and an estimated battery time.
Tap SHOW BATTERY USAGE to view a list of features and services that have consumed battery power since the last charging cycle. Tap any of them to see details of its energy consumption.