The updates only minimized phantom energy use & increased mileage for the most part. The C-Max and all other hybrids are just computers on wheels. They can not turn off total energy usage when not being driven. Our dealer has told us the battery is sized with the expectation of being driven within 3 days to keep the battery charged. We were sick once for over a week and the battery went dead sitting in the garage. When you are towing the key is on with a much higher energy usage thus draining the battery. There is a larger battery that can be installed but our dealer said they were not authorized by the factory to do the replacement. We will when the current battery reaches the end of its life. Also, on our rig, the charge line will not recharge the battery in the C-Max after it has gone dead. Had this happen once but had the charger with us and once I charged the battery overnight we had no problem on the next leg of the trip. Also remember this is not a Deep Cycle battery so every time the battery goes dead the battery does not charge back to the previous higher level. Each time the life of the battery is killed a little bit.
rocmoc n AZ/Mexico