To maintain the battery in the old car during lockdown. Albeit working from home I didn't travel much to begin with but this keeps the battery fresh without overcharging.
Looks like the stingers use an AGM battery, a big one at that. H7 for the 4 cyl, H8 for the 6?
Interesting side note. If your stinger is completely (and I mean completely) dead the front hood jumper connections don't work to jumpstart the car. I had to go into the actual battery area to get it jumped.