I have had one fail sitting on the grid for a hardship session and missed the race 6 hours from home so it can happen. I am told the reason they can fail is that unlike the stock rubber coated ones grit can get in under the metal and work into the rubber or whatever that is that holds the juice in.
Having had it happen is not enough to make me change them before they fail but it has made it so I carry spares with me so I don’t lose a whole weekend.