We had a cool morning (30F/-1C) here and my 2010 XC60 refused to start. It seemed to be low battery as I could not press the brake pedal but there's no "Low battery" message. The door opened with the remote control but didn't response to start engine button. I did jump start and ran a battery test which said the battery (2 years old) is in good condition: voltage=12.63V, rated 675 CCA, measured 637 CCA. This happened several times last winter. I took it to my dealer and they could not find any problems. I had no overnight electronic devices attached to the car. What could be the cause?