Pilot flying AEST aircraft reported electrical malfunction inflight. Returned to departure airport.

Narrative

A few minutes after takeoff from ZZZ and about 30 seconds after activating prop heat and cabin heat; the Aspen showed 'on battery power'. The voltage in the menu page confirmed this; as did the bus voltage. No alternator warning lights illuminated (at this point or any other time during the flight). Soon after; all the lights on the autopilot annunciator panel began blinking. About this time I asked ZZZ TRACON to RTB (Return to Base) and began turning off autopilot master; lights; etc. and cycled the alternator switches with no effect. Within about 5 minutes the clock; transponder; and both radios began blinking on and off. About this time I [requested priority handling] and turned off radio 1. Once radio 2 began flickering I cycled the battery switch as well with no effect. I heard a couple transmissions for vectors; but it was difficult to hear and I don't know if they heard all of my transmissions. The ILS signal was intermittent as were radio transmissions for the remainder of the flight and I relied on the intermittent ILS combined with iPad approach position to bring it in. Once the ILS signal was more gone than it was present (about 1500 ft. AGL) I cycled the battery and everything returned to normal. I turned on lights; contacted Tower and landed; returning the plane to the maintenance hangar. Had there been VFR weather close by I would have considered heading that way; but it was quite a ways away and the ceilings were high enough for me to try to RTB to ZZZ. Services were ready along the Runway but not needed.