How to Sync an Android Via WiFi Only
Tablets that use Google's Android 3 Operating system can use a lot of data because they can sync with many different things on the Internet, such as email, calendars, RSS feeds and social networking sites. If you do not have an unlimited data plan with a wireless network provider, you may incur monthly overage charges. You can set your Android device to only use Wi-Fi and get around these data charges.
Tap "Settings" from the Applications list on your device. Different devices have different ways of getting into the list. Your Home screen might say "Apps" or have an arrow that you can tap to get to the list.
Tap "Wireless & Networks."
Tap "Mobile Networks." You will see a "Data Enabled" listing with a check next to it. Tap the listing to uncheck the box. Your device will now only use Wi-Fi to sync.