Check the advanced options in Wi-Fi menu of settings, maybe the Wi-Fi sleep policy settings are set to OFF whenever SLEEP/SCREEN OFF. Change it to ALWAYS ON, or NEVER WHEN CHARGING. Tends to drain the battery a lot more, if set to always on. I use wifi manager by Kostya Vasiliyev (available in the Google play store) to get fast WiFi lock-on after screen on/wake.
Sent from my Transformer TF101 using XDA
MY OLD DEVICES
CURRENT DEVICE /S
Xperia Z C 6603
; Stock, LB, Root (101 F/W) (Mine!)
Xperia ZL C 6502; Stock LB, Root (101 F/W) (Wife's)
Nexus 7 (2012)Stock KK Root KOT49H(Son's)
Dell Venue 7 (2013)
Stock 4.3, waiting for Root (Ours).
Xperia JLo ST26i-Stock,Root (Son's)
Asus TF 101 ARHD; Root (Mom's)
Need Indian Fonts? Check my thread at http://forum.xda-developers.com/show....php?t=1560715