Battery failure results in a total loss of electrical power for a Cessna 210 pilot; the pilot subsequently landed on a closed runway under emergency conditions.

Narrative

Started as a local pleasure flight of about one hour. Upon returning I was unable to contact the tower; or anyone; on either COMM. I circled about a mile from the tower looking for a light. I never saw any light from the tower. I saw several airplanes in the traffic pattern for XX; the active runway. Runway XY had no traffic because it was closed for maintenance. Runway XY was clear except for a small truck parked the edge of the runway. Dealing with a small truck on the edge of XY seemed much less risky than several airplanes on the active Runway XX. It turned out to be battery failure. However; at the time I didn't realize that and it didn't manifest itself all at once. I could receive but could not transmit. Then other failures occurred. Eventually I had no electrical power at all; not even gear lights. I had started the flight with 50 gallons of gas but seeing the gauges at zero didn't help. The stress was beginning to mount. I wanted to get on the ground quickly and as safely as possible. I felt that I had a real emergency. I landed on Runway XY; the closed runway; without incident. After parking the airplane I called the tower on the phone. Discussing what had happened he said I should have flown past the tower while rocking my wings to get his attention. Then he would have cleared the traffic pattern and then would have given me a green light to land. In more than forty years of flying I have never had a COMM or battery failure. The fly-by the tower procedure didn't occur to me. I was uneasy getting with in even one mile of the tower without clearance.