approach s60 battery

So I've had my s60 for around 3 months now and its been fine. Yesterday was the first day I'd played 36 holes in a day since purchase and the battery died on the 10th in the second round which would have between 5 and a half hours. Is this normal - I'd have expected it to last both rounds. I then set it to charge when getting home and left it all night but it only took 3%. Have now restarted and have the charge symbol back on the screen so hopefully its going to charge back up but is taking a while to move from 4%. Does this sound like one of the issues where a restart will fix or a bigger problem?