C182 pilot reported a generator failure resulting in landing at the destination airport with limited communications with ATC.

Narrative

I was flying from ZZZ1 to ZZZ to take the aircraft to Maintenance to have some new avionics installed onto the aircraft. I taxied the aircraft out; did my runup checks and everything including the charging system operated as normal; reading 13.5 volts. I took off out of ZZZ1; 15 minutes into the flight I noticed the radios starting to flicker; I looked down at the volt meter and it read 9 volts. I immediately turned everything off except com 1. The transponder screen had already gone blank. I tried to look up the phone number for ZZZ Control Tower; but had no cell phone service and no hand held radio with me. I attempted to contact ZZZ Control Tower on com 1; they could hear someone was trying to reach them but no audio signal; only carrier wave was coming through. I could hear ZZZ Control Tower just fine. After a couple minutes I decided to head towards ZZZ to see if I could get through to them; As soon as I penetrated the Delta; they reached out to me with my tail number; I tried to respond but to no avail. they asked me to Ident if I needed assistance; I pressed the Ident button on the transponder; a couple minutes later I heard ZZZ Control Tower say they did not see my ident. As I got closer; I called out on the radio a couple more times and they told me they were barely able to hear me. I let them know I lost my generator and was on battery power but losing that quickly. They cleared me to land and I landed on XXR; They rolled out the fire trucks as soon as I landed; I taxied off on Taxiway 1 to the non movement area and as the trucks arrived; they looked at me and gave me the thumbs up and I gave them the thumbs up back and they went back to their garage and I taxied on to the shop.