Assumption was my GF’s kid left something on because it was fine the day before. Overnight charge only lasted a few hours. I could not find anything left on. The replies to my post confirmed the battery was around 4 years old so decided to swap it out with an O’Reillys. It’s been holding at 12.6 for about 5 hours without a charge so I guess the battery decided to fail suddenly one day.
Or.. did disconnecting the battery for a while swapping batteries reset something that was causing the drain…