I had purchased Inspiron 15R 5521 in January 2014 which suddenly has started showing "Battery Permanent Failure,Press F1 to continue" when I turned it on this morning.
This is comparatively very short battery life as my brother has a Samsung which is an older piece then mine but still can run on the battery and one my friend has a Dell XPS which is even older but has a working battery,
Thanks for posting.
I apologize that your battery isn't lasting as long as you expected it to. Batteries normally last between a year and 18 months under normal use. Dell provides a 1 year battery warranty which is described below:
Batteries for portable systems and mobile devices are not covered under the same terms as the system warranty. Agents should see the procedure below for determining the warranty of the battery in question.
Hope this helps.