AC Delco was our main battery supplier up to about 5 years ago.
Warranties suddenly changed from 2 year free replacement/5 year prorated to 18 months free replacement on the consumer line.
And shortly after that, we started to see failure rates skyrocket to the point where we changed our main battery supplier.
Delco isn't the only one with issues though. This winter, I've lost count of how many 2015/2016 model year vehicles that came in with bad batteries.
Now - 2018 Equinox 2LT 2.0T AWD
Was - 2015 Equinox 1LT 3.6 AWD