Super King Air 200
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 90; Flight Crew Total 7500; Flight Crew Type 1200
Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Issued New Clearance; Flight Crew Diverted; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Landed in Emergency Condition; Flight Crew Landed As Precaution
Aircraft
Approximately 20 minutes into flight received various error messages on MFD; engine instruments began to fluctuate; auto pilot disconnected; then the loss of all electrical power. All of which took place within minutes. Tried to regain electrical power to no avail; all non-essential electrical items where shut down. Turned off flight path toward [a suitable alternate] in search of broken cloud layers; utilizing standby attitude indicator; whiskey compass and ForeFlight iPad. Advised passengers of situation and that all was under control. Upon finding suitable visibility began spiraling descent out of altitude. When altitude permitted texted company Duty Officer and notified him of situation and requested he contact ATC and Tower advise them of situation and request permission to land. Minutes later received cell phone call from Tower and were given permission to land. Tower was able to advise us of our airspeed; crew manually extended landing gear; flew by Tower to confirm gear was down. Landed aircraft; taxied to parking.Flight crew utilized CRM to work the problem; unknown at this time the cause of problem.
B200 Captain reported diverting to an alternate airport after experiencing loss of all electrical power.