2013 Ford C-Max Energi SEL 4dr Wagon (2.0L 4cyl gas/electric hybrid CVT)
I purchased the C-Max Energi with the thought of driving the vehicle only a few miles per day, plugging it in at night, and almost never having to visit a gas station. The big problem with that is the lithium ion battery is charged, but the 12 volt battery which initially cranks the engine isn't being charged at the same time. So what happens? You go out to start the car, and the 12 volt battery is dead because the 12 volt is gradually being drained. The local dealer said that's the case because the Energi has no alternator. So if you don't drive extended miles every few days or so, the 12 volt battery will gradually be drained. This happened twice to me.
The Energi drives and handles well, is quiet, and has more than adequate acceleration.
This is a software issue. It could be tweaked so when the car is pluggen in, it not only charges the lithium ion batter, but also trickle charges the 12 volt battery. I sold the car after two months, absorbing a considerable loss because of this issue. Who wants to go out and wonder every day if the car will start?
This condition does not sound normal, instead it sounds like you may have had a power leak on the 12V circuit (defect on a electronic component or a sticky relay maybe). I would have measure the current drain on the battery to get data points when the car is stopped and running to get data point, and I would have had the car check with another dealer (I does not sound to me that the personnel you dealt with was very helpful - unfortunate that this translate to the review of the vehicle) and brought up the case with Ford Customer Relations. I have had my C-Max running on electric only for couple weeks and after 18 months never had the 12V battery go weak. The 12V circuit is charged by the high voltage battery during electric use through DC-DC converter.
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