I just bought my wife a 2014 C Max and it is our first hybrid. We feel it is not getting the fuel mileage it should be. It has just under 81000 miles. We seem to be getting about 31mpg and can't get it any better and I am pretty good and driving economically and have been doing everything I can to get the best mileage. If driven "normally" it would be getting worse mileage. Would a weak hybrid battery cause this? The battery meter drips really fast and if you turn the key on to accessory the radio turns off within minutes and says it is due to low battery. Any input would be appreciated.