I have Kindle Keyboard 3G, I use the text to speech for reading books while commuting. If I leave the wireless turned on it uses up the battery pretty fast trying to keep and or find a 3G or WiFi connection.
I would like to modify the behavior so it does not try and use the 3G and only checks for WiFi once an hour or so. If it does not find WiFi it should wait an hour before trying again.
Your Kindle automatically turns 3G coverage off when you connect using Wi-Fi. When you disconnect from a Wi-Fi network or if you move out of Wi-Fi range, your Kindle automatically switches back to 3G coverage.
For Kindle models that include free 3G, wireless connectivity is automatic (with no monthly fees or annual contracts). If you see one of the 3G network indicators (3G, EDGE, or GPRS) in the upper right corner of your Kindle screen, your Kindle is already connected wirelessly using 3G.
The general help does not seem to include any directions for modifying the wireless habits. A solution that does NOT permanently disable the 3G would be preferable.