I was sitting in the car for about 10 minutes waiting for the wife. At first I just put the car in park and let the engine (with A/C on) cycle on & off as necessary. After a few minutes I decided to shut the car and just place it in IG-ON mode. Now my question: Will the engine continue to cylce on & off in the IG-ON mode to keep the main battery charged at an acceptable level? Thanks! Marvin
Evan, thanks for your reply. Doesn't the A/C run off the main battery and not the 12v battery in IG-ON mode? Thanks, Marvin
The A/C runs only from the traction (main) battery, but the point is that you can quickly drain one or both batteries in ACC or IG-ON, because the engine will not run to keep them charged. If you're going to be in the car just leave it ON, as though you were going to be driving it, and shift it into Park (NOT Neutral! The batteries don't get charged in Neutral). That way the engine will start as needed to keep everything charged up and the will car manage itself as it was designed to do. Of course you should not do this if you are parked in a completely enclosed space with no provision for removing the exhaust.
I don't think there's any way you could drain the traction battery in IG-ON mode as it's only connected in Ready mode. You can prove this for yourself by putting the car in Ready mode and listening for the click of the relays coming from the back of the car. Then turn the car off and put it in IG-ON mode--you won't hear the relays click.
