I dont see a market for this either.
Just set up a reminder at work and on your mobile phone to top the emergency phone every 11 months.
Also - your emergency phone wont have recent contacts updated (who remembers phone numbers these days!) , so in the hours after an emergency you may just have calls and text, and any refresh of contacts data may be delayed.
A case could be made that the emergency phone should be non-smart to get a better battery life also.