colder temps will take a toll on the chemical processes inside the battery, even though 10 C is not THAT cold... if the battery is over 3 years, it is worth it to see if a new battery is in order... if the battery is 5 years old, chances are higher you need a new battery.. if you've got an original one - definetely need new one...

monitor your under load voltage to see how battery performs... sometimes there is a bad cell (there are six cells in the battery), that drains battery internally... even new batteries may have a bad cell...