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2012 Lincoln MKZ Hybrid 12 volt Battery Warning problem We have enjoyed our 2012 MKZ Hybrid since July 2011. It has performed virtually without a flaw now for 44,000 miles. Last week, my wife began to intermittently receive a momentary “Battery Warning” chime with about a one or two second red warning display on the very left hand side of the display (where the temp is normally displayed). This warning happened perhaps a dozen times over several days. It always happened when the car a) slowed down almost to a stop and then b) a very light acceleration (electric only) was called for. I found I could repeat this several times in a row but not EVERY time I tried it. I also have a 2010 Ford Fusion Hybrid, and something that reminded me of this problem had happened to me early last year. If I stopped for a while and left the AC running on the car while stopped, the battery voltage dropped and my dash display would go back to factory defaults. In that case the dealer did not have a clue, but I found the answer in the forums.. That was: Replace the 12v battery and install a particular TSB. That DID fix the Fusion Hybrid 100%. I took TWO trips to the dealer and they were unable to diagnose the problem. I then found the problem on the Fusion Forum, changed the battery, and had the dealer put in the TSB and all was well. I did not want to repeat this experience where the dealer charged me for non-productive diagnostics. With that in mind, I asked my wife to drop in to our Lincoln Dealer to have them check it out. I was pretty sure that by this time, this would be a known problem and easy to fix. This was not to be! They claimed never to have heard of such a problem. I went to the Internet and found a number of forum entries reporting “Battery Saving Warning” alarms and found a TSB that was supposed to correct this in 2013 vehicles. I took the car to my dealer and I said: Please install a new battery in the car, install this TSB and check the charging system for any defects. I was told: “We cannot do this without running complete diagnostic tests”. OK says I. Just install a new battery and install the applicable TSB and I will pay. Don’t worry about the warranty. They refused even though I told them they would have no responsibility if this failed to fix the car. I was pretty frustrated that they were going to take 2 days to do this, so I took the car home to do some troubleshooting. Since I am an Electrical Engineer, I knew what to look for. I found that: 1) When the car “alarm chime” happened, the car had just accelerated slightly in electric mode from a near “stop” and apparently the 12v battery charger which runs off the 277vdc battery stopped supplying current to the 12v battery momentarily as the car accellerates in "electric mode". 2) When the charging stopped, the voltage of the 12v battery dropped, for just a few seconds, below 12vdc and the chime alarm sounded along with the warning display. After a second or two, the charging resumed and the voltage on the 12vdc battery went back to the range of 13vdc and the chime and warning stopped. 3) I replaced the 12v battery with an off the shelf battery (after modifying the battery carrier which was designed to ONLY accept the “especially shaped, but ordinary” Ford 12v battery. Following the battery exchange, the car performs normally without the alarm chime problem. It appears that there is a software bug in the alarm logic, which causes this problem. However! The battery did check “bad” and was ready to be changed out. But the Battery alarm logic could be written to give a proper warning of a failing battery and not leave these obscure failures for people without electrical knowledge to hassle with! FMC should also have a try at training their dealers to a) be KNOWLEDGABLE about these obscure warnings and problems and b) simply ACCEPT THE ORDER AND THE MONEY if and when a knowledgeable customer comes in and wants a specific part (such as a battery) changed out! I would quite quickly accept just the “Make the service consultant KNOWLEDGABLE part!!! How about it FORD!!?? PS> The service manager told me these vehicle forums were FULL of misinformation and could not be trusted! For my own part, I find these forums quite useful and overall very accurate when read carefully.