Some watch technology made its over into the phone
The Chairman's coolest special feature also nods back to Ulysse Nardin's horological past. The crown and rotor you see on left side of the phone is not meant to adjust the time, it's meant to power a second battery that collects the kinetic energy from when the rotor is twisted. Without the second battery, the Chairman notches seven hours of talk time and 30 hours of standby time. When you have a phone made out of gold and diamond, the last thing you want to do is cover it with a battery case.