This issue is ridiculous since the car is supposed to charge the battery, not the owner or the dealer. I had the battery replaced in January and the TSB 13-5-1 done and still have the problem. Dealer is contacting Ford again as there is nothing he knows to do, sadly. So, since my battery voltage was 11.9 and a voltage below 12.15 causes battery saver to kick in, I put mine on the lawnmower's charger over night to see if it will take and hold a charge. Now reads 12.74. In theory they checked the battery when TSB was done but who really knows. I asked the service manager to check with Ford about a reprogram of the battery saver software to allow for a lower charge point on the battery since they can not fix the true battery issue. Would really like correctly functional windows and accessories working in accessory mode.
IMHO the battery is way too small for the load that is constantly applied to it. (multiple computers, alarm system, and who knows what else. The CCA designation is strange because this battery is not used to crank the engine. The battery should be a deep discharge battery such as a marine battery as opposed to a normal car battery which is designed for a short burst of high amperage and then immediately be recharged. Hence the CCA rating.
The battery is proprietary to Ford and there are no specifications published anywhere that I can find. The only place a replacement is available is from Ford.
The same was true of the 12 volt battery in my 2010 Fusion Hybrid.
I have a 30 ampere battery charger that displays the battery's state of charge while it is charging. After the car sat for 2.5 days the battery was down to 37% state of charge. A deep discharge battery will maintain it's voltage much better than a standard car battery will as it is being discharged.
My car is scheduled to get the TSB on Wednesday and I will rerun my 2.5 day test after it is installed. I don't expect much to change because the battery was fully charged before I ran the 2.5 day test.