Cessna 210 pilot reported experiencing an electrical system failure during departure climb at night. Pilot returned to departure airport; performed a manual landing gear extension and landed.

Narrative

I departed ZZZ at XA:42 in VMC night conditions; after departure I contacted ZZZ Departure on XXX.X and was given a heading of XXX and a climb to 13;000. Upon reaching 9;000 I requested a right turn and was given a clearance direct to a fix on my route. At the same time; I noticed my instrument lighting got dimmer and the low voltage light had illuminated. While trying to troubleshoot and reset the alternator I noticed I lost my HSI which was quickly followed by the loss of all the digital screens on my radio stack; Garmin 530W; Kx-155; Garmin XPD. As I was no longer in Class B airspace and in VMC conditions with ZZZ in sight I turned south and started descending. I thought I had lost all the radios due to the blank screens but I heard ZZZ Departure Control try to contact me and I tried to respond. My transmissions seemed to be intermittent. I was able to tell ZZZ Departure Control that I was returning to ZZZ and would remain clear of Class B airspace.Upon entering the crosswind leg of the traffic pattern for Runway XX at ZZZ I lost all electrical power which required me to manually extend the landing gear and make a no flap; no landing light; approach and landing.After parking the aircraft I called ZZZ TRACON and talked with the controller and ensured him all was good and thanked him.After the event; Maintenance found the battery to be bad and that the alternator had failed. Both were replaced and operationally checked OK.