Join Date: Feb 2017
Location: East TN Sevier County is Near Knoxville
"""How long were you sitting in the car? I've done this a few times and after a minute or two the engine has kicked on, I'm guessing to help keep it cold air."""
NJ Niro --
I would say the engine starts to recharge the battery. Battery of course discharges when sitting with anything running and I expect quickly if AC is running.
I was siting waiting for my wife (she was in WALGREENS Drug Store for a short time) and listening to music with system on (dash lights, etc.). Eventually (maybe 5 minutes) the engine started, I noticed the battery was down to say 40%.
By the way, if you run on Accessories Only (say for radio) -- you get a warning that you may discharge the battery and recommendation you turn the system on.