Citation X (C750)
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Declared Emergency
Aircraft
During cruise; we had a BATT 2 OVERTEMP Red CAS message. We immediately followed the memory items and turned the BATT 2 off.  Then we consulted the Emergency checklist. Initially the Battery Temp started to drop; then after a few minutes of monitoring; it started to rise. At this point we decided to divert to the nearest airport in which we could descend from 41;000 feet.  We contacted ATC and declared an emergency; contacted the company advised them of the situation.
CE750 First Officer experiences a battery over temperature at FL410 and disconnects the battery. Initially the temperature drops then starts to rise and the crew elects to declare an emergency and divert to a suitable airport.