[keep_hope_alive]

This kind of system has been in place in Hondas since the 1990's. In a Honda the load sensing device that is used to tell the PCM to turn on the alternator field current is the ELD or Electronic Load Detector. The ELD monitors the ignition circuit and things like lighting or A/C can result in the alternator being "on". Originally, the alternator would be either on or off, and users found it annoying that their headlights would dim. Since 2013 they started regulating the "off" output to 12.5V which prevents battery voltage from dropping below that (they could get to 11.9V on the old system).

I'm intrigued. I developed a bypass for the old Honda system. I'll look at the charging schematics and see what the PCM is looking at to make the determination to turn the alt field current on or off.