Your cup of your favorite hot beverage has gone rather cold. While you do not have an easy access to a kitchen right at this moment, you happen to have a phone, wires and other small tools. Remembering all sorts of trivia, you know that your cellphone battery holds 11.1 Wh (watt-hours) but only 30% charge remaining. Is there enough to heat your coffee and still have enough power to call your friends? What is the absolute minimum of electrical work that is required to heat your coffee cup