Skyhawk 172/Cutlass 172
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Flight Instructor
Flight Crew Last 90 Days 35; Flight Crew Total 20000; Flight Crew Type 1000
Aircraft Equipment Problem Critical
Flight Crew Diverted
Aircraft
While operating on a VFR training flight out of ZZZ; I noticed the voltmeter on the aircraft was beginning to fluctuate slightly. We decided to continue flight but eventually noticed the volts were dropping significantly. At the time we had been in contact with Approach but decided to turn back to ZZZ and notified Approach we were turning back hoping to avoid any serious problems. Within minutes; we notice the volts had gone below 10 volts. At that time; we decided to head to ZZZ1 because it was closer; we were also worried about losing all electrics at night. As we started our initial approach into ZZZ1; we lost all electrical power; transponder; radios; electric instruments and lighting. We decided to continue and eventually landed at ZZZ1 without any problems. After a few minutes we located a phone number for Approach; we were able to contact them to let them know we were alright.
C-172 instructor reported aircraft electrical failure during a training flight.