Why is the battery on S5 draining so fast since upgrade to Android 5.0? Plus other app problems

[AC Question]

Main problem is that since the upgrade, Google Play Services (6.5.99) is now using 39% of battery and drains the battery in 12 hours. Phone is getting really hot. Cannot disable Google Play Services.
Other problems are that the phone keeps switching from my WiFi to 4G even though WiFi is operating fine and phone is within 2ft of WiFi.
Messenger now takes over 5 minutes to send an SMS (There have been no changes to mobile account/mobile network/etc)
Plus, Contacts and a couple of other "onboard" apps keep crashing.

 

[belodion]

Possibly, Settings, Wifi, 3-dot menu, Advanced Wifi, Smart Network Switch will help. Uncheck/untick it.

Other treatment may be necessary. Get back to us if so.

Posted via the Android Central App

 

[JerryWills]

Thanks. Have unchecked Smart Network Switch and will see that that does. Appreciate the assist.