SM City Batangas is now wifi-enabled. They have free wifi almost mall-wide. Wifi signal is strong, even at the parking area at the back side.
Wifi signal is strongest at the food court. If you have a laptop with wifi capability and want some free internet, simply go to SM Batangas City food court and enjoy!
I say almost mall-wide because there are some areas with no wifi signal like those restaurant area where KFC, Chowking, Pizzahut and Starbucks are located.
Note that this is based on my wifi testing using my Nokia N79 cellphone. Your results may vary depending on the device you use.
They launched their free wifi service last August 21.