I just had to change the battery in my '16 . You have been charging the battery, now it's time to replace it. I was not happy the OEM battery only lasted 3 yrs. myself.
Not trying to “troll” you here (LOL!), but another data point for you: just recently replaced the battery in my ‘02 Impala: just a couple months short of 7 years!
Now *that’s* highly unusual for me. I usually get 5 years+, though ... in the heat of the Carolinas. Up in New England, I don’t think I got past 4 years most of the time. They say extreme heat AND cold kill batteries, but my data say extreme *cold* kills them more.
BTW: It was an Advance Auto “Silver” Line battery (their mid-grade level). Probably just got lucky. Didn’t even buy another one for the replacement. Just went to Walmart for one of those EverStart Maxx batteries. I’ve had one of those in my Nox for around 4 years now...
2011 Equinox 1LT (dlvd. Jan 2011): Summit White / 3.0 L V6 / FWD / Pioneer Stereo / 18" Wheels / 142k miles [01-FEB-2020]
2002 Impala 1LT (dlvd. Jun 2002): Summit White / 3.4 L V6 / FWD / Cassette-CD Combo /228k miles [01-FEB-2020]