I have tried to research this all day to find out what the maximum sizes for Android and iPhone are. On the current Android 4.x phones the limit seems to be fixed at around 8MB, effectively limiting you to storing json-content of up to 4 million characters (each character is 2 bytes in utf-16).
No Android device I have tested will prompt you when you hit the limit, as opposed to iPhone, which will prompt you both at the time of database creation (with a size >= 5MB) and when you hit each of the limits (5, 10, 25 and 50 megabytes).
You can create several smaller databases, but it will not help you in increasing the total storage on Android which is still limited to 8MB. If you are running in a WebView, that is another story; There you can store up to 50MB on Android, and the same on iPhone (in a UIWebView) - WITHOUT getting prompted.
PS. You might be able to cram the 11MB of data in 8MB if you compress the strings. Do expect approximately a tenfold decrease in read/write speeds. See http://labs.ft.com/2012/06/text-re-encoding-for-optimising-storage-capacity-in-the-browser/