Raja- you were right. It only aplies to low FOB battery.
I found this video on yt that might be the root cause of the 12v battery issues:
After testing, they found out that his c-max energi had a faulty ACM (Audio Control Module)which was drawing 400mA when the car is turned off. I am suspecting that mine also has the same problem. A year or so ago, I had an issue with the radio staying on despite attemps of turning it off or powering down the car itself. The radio controls did not work and I could not change the station, adjust the volume etc. even when the car is running or not. It happened to me 4 times the first time it just went away. The second time, it drained the 12v battery and I had to jump start it. FInally. I pulled the fuse # 79 (and re-installed) for the ACM and I was able to reset it and the did the same the 4th time to fix the issue. However, recent dead battery experience did not have the radio staying on symptom. What I'm suspecting is that the ACM just like the man above in the video was stuck and did not power down. This resulted in current flow even when the car was turned off. I do not have time to replace the ACM but what I did was remove and replace the # 79 fuse. I don't think there was an issue with the fuse itself but removing and plugging it back will reset the ACM.
This morning I did not plug in the charger and left the car outside the garage and It started fine.
Edited by bembem88, 05 September 2017 - 06:50 AM.