I've had electric fans in other brands (vw, acura, infiniti) where the fan would continue to run after turning of the vehicle including my Cadenza. I don't think it ever ran for more than 30 seconds or so. I've noticed it more when creeping along in heavy traffic to get home during the summer with a/c running. When I park in the garage and shut off the car, I can hear the fan running while getting out. I've had mine 2 years now and have never had an issue with the battery yet.
Found a mention of this in the Owners Manual on page 7-31:
The electric motor (cooling fan) is controlled by engine coolant temperature, refrigerant pressure and vehicle speed. It may sometimes operate even when the engine is not running.
2014 Cadenza Limited
Snow White Pearl w/White Nappa interior
Last edited by GizmoPDX; 02-23-2016 at 10:20 PM.
Reason: Additional info