A Bonanza V35 pilot reported generator failure ten miles from their destination and continued to land.

Narrative

I was operating the aircraft with a certificated flight instructor onboard on a flight from ZZZ1 to ZZZ Approximately 10 nautical miles from ZZZ; we experienced a loss of normal aircraft radio communications. Initial troubleshooting; including verification of circuit breakers and system indications; suggested reduced generator output and insufficient electrical power to reliably support installed avionics.In accordance with standard procedures for a communications failure; we selected transponder code 7600. A handheld radio carried onboard was then used to establish communication with ZZZ Tower. After assessing available options; we elected to land at ZZZ. As a precaution; the landing gear was extended manually in accordance with approved procedures. Tower personnel visually confirmed all three landing gear were down while the aircraft was on downwind. The landing was uneventful. After shutdown; we contacted the tower from the FBO. The aircraft was subsequently inspected and repaired by Company A at ZZZ. The direct cause was a failure or severe under-performance of the aircraft's generator system; resulting in a total loss of electrical power to the primary avionics. The root cause of the generator issue was unknown to me and was determined by maintenance personnel after the flight.Maintained aircraft control and aviated first. Performed immediate troubleshooting (breaker check). Squawked 7600 to indicate lost communications.Utilized a backup handheld radio to reestablish two-way communication with ATC. Briefed and executed the manual landing gear extension procedure.Coordinated with ATC for gear confirmation and landing clearance.Landed at the nearest suitable towered airport with maintenance facilities.The aircraft was repaired by qualified maintenance personnel before further flight.Redundancy Saves: This incident underscores the critical importance of carrying backup communication equipment. A handheld radio proved invaluable in reestablishing ATC contact and de-escalating a potential emergency situation.Proficiency: Regular practice with abnormal and emergency procedures; such as manual gear extension and lost comms; ensures calm and effective execution under stress.Pre-flight Risk Mitigation: This event will reinforce my personal minimums to include a thorough pre-flight check of all electrical system indicators and a review of the aircraft's recent maintenance history for any recurring discrepancies.