Originally Posted by martysmartie

As I say get the battery tested, if the battery has had it then it won't be able to hold a charge, hence after it's charged it's fine for a while, from what you have said so far I would say the charging system is ok and before you think it the fact it's not that old means nothing, if it's been deeply discharged a few times it will kill it!

The classic sign of a bad rectification is the battery light stays on when the ignition is switched off.

Martin