Small Single Engine Pilot reported an alternator failure. The pilot diverted to a nearby airport with assistance from ATC.

Narrative

On our trip from ZZZ to ZZZ1; my crew partner and I noticed that the alternator failure annunciation light came on. We were cruising at 6;000 ft. in day VMC conditions. OAT was 10 degrees Celsius. We were leaned out for cruise flight and aircraft was performing as expected. Once the light came on; we verified with the ammeter; which was reading 0; that the alternator had failed. We immediately referred to the emergency ALT Annunciation Illuminated checklist and began going through it. As per the checklist; we turned the Alternators off; reduced loads; checked the circuit breakers and turned the Alternator back on. This was the first time going through the checklist and it seemed to work. The Annunciation light had turned off and the Ammeter showed a positive charge +11 and +12 amps.This held true for about 10 minutes and we noticed the Annunciation light came back on; and again the Ammeter showed O. We ran through the same checklist again and the annunciation light once again turned off and the Ammeter showed a charge of +11 amps. This time however; the charge only remained for about 1 minute and we decided that the Alternator had indeed failed. We decided to [advise ATC] as we didn't know how much time we had left on battery power. We had noticed that ZZZ2 had just passed off of our left wing. As we were talking to Center; we asked to divert to ZZZ2 and we made a landing on Runway XX. As I was PIC (Pilot in Command) and at the controls of this flight; I did notice a slight difference in engine power on Short Final. A little buffeting was felt through the controls as I throttled up but the engine continued to run until Engine Shutdown.