I have Asus pu500c laptop with Intel Corporation Centrino Advanced-N 6235 (rev-24) network controller. My wifi works fine when my laptop is charging. But when I disconnect the charge after some time my wifi stops working. Only reconnecting to the wifi network can help for a while.
sudo iwconfig wlan0 power off
and uncheked 'Prefer power saving over performance' in xfce4 power manager. I hope it will help.