After seeing the coin cell challenge, there is now a potential to get some juicy prizes! However, the one issue with my project is the solar cell, which would be a separate power supply, therefore disqualifying my project in its native form. However, I think it could be fun to temporarily disable the solar cell, making my project a legal entry to the competition, but also allowing me to test the battery life of the watch given the worst possible charging conditions: no power at all.