Pilot reported an electrical failure while en route that affected the operation of the landing gear and made communications difficult. The pilot was in contact with ATC and a gear up landing was accomplished.

Narrative

Date; I departed ZZZ at XA:05 PM. I did my pre-flight inspection. Everything checked out fine. I did my pre-taxi checklist. And got cleared to taxi to Runway XX. It was an ideal day for VFR flying. The winds were calm. The skies were clear. For the departing airport; on route and my final destination of ZZZ1. Hence; I did not file an IFR flight plan; but I did request flight following under VFR. The aircraft holds 89 gallons of usable fuel. I chose to depart with half tanks at 44 gallons; plenty of fuel for the short 105 NM trip. Upon completion of my run-up checklist and everything checking out normal. I got cleared for take-off and instructions to proceed on course. I climbed to 4;500 feet. Went through my cruise checklist and configured the aircraft to cruise settings along with the autopilot. About 40 miles from my final destination (ZZZ1); the autopilot disengaged. I was fixing to start my descent to 3;000 ft. With the auto pilot disengaged; I began to hand fly the airplane with no issues to maintain heading and altitude. Shortly after the autopilot disengaged; the transponder went out. I immediately shut off the aircraft lights (strobe/beacon). I was communicating with Center at the time; and they asked me to IDENT. I responded; 'Unable and experiencing electrical issues'. The Garmin avionics started to shut down and re-start. They flickered five or six times before the Garmin 750 shut down for good. I noticed the fuel gauges were no longer reliable as they showed a significant drop in fuel quantity. I was struggling to communicate with Center but maintained contact. They asked to change frequencies; I responded 'Unable'. They stayed with me on the current frequency; and with my location and struggling communications; I prepared to call ZZZ1 Tower from my cell phone to get clearance to land. I announced to Center that I had the field in sight for ZZZ1. They connected me to ZZZ1 Tower via the Guard frequency to get my clearance to land. I got my landing checklist and got myself set up on a right base to land XYL. ZZZ1 Tower cleared me to land. I was turning final and descending through a 1;000 ft. I pulled the gear down-nothing. The ammeter was showing a negative charge; hence the electrical issues. The alternator was clearly out and there was not enough power to operate the landing gear. I tried the gear again; with failure to extend; and took note of my position. I was very much on the final leg; descending to land. I announced to the tower that my gear was failing to extend. They confirmed it for me by sight. At that point; I did the best I could in the situation I was in; and I prepared myself for a gear up landing. The emergency checklist for a landing gear failing to extend calls for extending the emergency hand pump and pumping it for 86 cycles. I knew with my position in the pattern-pumping the landing gear 86 times was not practical. And attempting to pump the gear could possibly result in a worse outcome for the aircraft and myself with a partial gear down landing. I slowed the aircraft to approach speed on short final; glided over the runway-I turned the fuel selector valve to the 'OFF' position (per the emergency procedure for a gear up landing in the POH). I held off ground contact as long as I could to slow the aircraft and landed. The aircraft slid down the runway in a straight line and came to a stop. Tower announced I could exit the aircraft. I went through my shutdown checklist as best as I could and exited the aircraft. Contributing factors to the gear up landing: The electrical issues and failing communications distracted me before I approached the airport. I should have attempted to pump the gear before I was in the pattern and preparing to land. This was my first time experiencing an emergency procedure or any sort of failure in the aircraft. I could have opted to request to re-enter the pattern to re-assess my new challenge of a landing gear failing to extend. However; with the deteriorating systems in the aircraft and though; I knew I had enough fuel; the gauges were very much un-reliable and I knew I also didn't have fuel for days to expend. The emergency checklists provided in the POH will be referred to immediately following any issues moving forward.