Charger kicks on when I open the door

[Fat Focus]

When I go out in the morning to drive my Focus, I have to unplug the car before I open the door or the charger will kick on. The car is fully charged since it's been plugged in overnight and has 5k miles on it. My Fusion Energi never did this. It's not a big problem, since I usually just unplug it before opening the door. But, sometimes I have my arms full and want to throw the stuff in the car then swing back and un-plug. What is your experience?

[jmueller065]

Yes this is not an issue. It is the EVSE that kicks on NOT the charger (the charger is actually in the car).

It will do this if you pre-condition the car or remote start it while its plugged in. Again this is NOT the charger. It is something you want: You want the car to draw its power from the wall while its plugged in preserving the HVB for your drive.

What is happening is the car is kicking on the DC-DC converter providing 12V to the systems in the car using the wall power instead of battery power.

[Fat Focus]

So everyone's car does this? Sounds pretty lame. It's not like opening the door and the tiny little 12v light is drawing appreciable current.

[jmueller065]

So everyone's car does this? Sounds pretty lame. It's not like opening the door and the tiny little 12v light is drawing appreciable current.

Yes everyone's car does this.

Not just the tiny little 12V light, opening the door pretty much wakes up the car. Plug in an OBD2 reader and use Forescan to watch all the modules wake up when you open the door.

[triangles]

Yep all FFE do this. FYI the battery coolant heater is (3) 300W 12V heating elements. Also when you plug in when it is cold out you will hear a faint hum almost like the sound of a distant leaf blower. I don't know for sure what this is but I believe it is the charger deliberately running in an inefficient manner to generate more heat for the battery. It would be nice if Ford had publicly available documentation that is very detailed as to how the systems work so that us curious tech nerds can know for sure what our FFEs are doing.

[Fat Focus]

Thanks for the info guys. I'll just try to remember to unplug it first. It doesn't get too cold where I live in Nor Cal. I'm at 700 feet and about 30 miles from the Pacific. I probably won't even precondition the car. 29 mile commute each way.