Cessna 182 pilot reported diverting to an alternate airport after experiencing loss of all electronics.

Narrative

Enroute IFR Flight from ZZZ to ZZZ1 via ZZZZZ and ZZZZZ1 then direct to ZZZ1. Climb and routes took 50 minutes to get to cruising altitude of 11;000 ft. and direct to destination. Once I reached cruise altitude and was on course I noticed high voltage light; decreasing battery voltage; and backup battery monitor. I immediately informed ATC of the issue and they recommended a descent to 4;000 ft. which was VFR on top and they decided to [request priority]. I was directed to ZZZ2 and was offered the ILS XX approach with ceilings of ~1;200 ft. While enroute to ZZZ2 and coming up to the airspace; all electronics were lost. This put me in a situation where I would be unable to safely and legally shoot an approach into ZZZ2 without GPS capabilities. I used foreflight on my phone to locate the nearest airport to me where I knew that the ceiling was 2;000 ft. from weather in app (higher than destination ceiling). Without having any GPS capabilities; any NAV source; comms; or a reliable way to shoot an approach into ZZZ2; I decided to descend below the clouds to perform a visual approach into ZZZ3. I made a safe visual descent and landed after having performed an emergency gear extension. I immediately called FSS upon landing to inform them that I was on the ground safely.I went to an area where clouds were thinner to try to re-establish VFR. Without a way to know that weather would hold at the destination; I chose to get the plane on the ground as soon as possible to avoid entering a towered airspace with more traffic.