How viable would it be to use a transdermal like @Leeborg 's project ? Plug a charger on to the transdermal to power the storage? I thought about some kind of medical-type port (but much smaller) but then there’s the whole risk of infection thing to worry about. Perhaps I’m thinking too far into the future 
I feel like I’d be more worried about snapping the storage chip in some kind of fall / blunt force trauma.