Hi XXXXXXXXX.
Thank you for asking your question on Just Answer.
Ford has a TSB that deals with the problem your having, Im sending it to you for your review.
DOWNLOAD HERE
ASE Certified Technician
23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
Any vehicle that doesn't get driven enough will have a battery problem. Consider this, when you start the engine you pull close to 200 amp out of the battery for the few seconds that it takes to get the engine running. While driving, the alternator has to recharge the battery as well as supply enough power to operate the vehicle, lighting, stereo, etc. It normally takes about 1 hour of driving to recharge a battery from each start. If you are allowing the vehicle to sit for extended periods of time, you add the load of the computers and systems memories that are always on. Without ever getting enough power into the battery. You have two options. Drive the vehicle more. Or get a trickle charger and keep the battery charged up