Right. In answer to Rewe6a, I replaced the battery today with a new Bosch one. And the battery light still stays on for 5 minutes or so from cold start up! This gave me an opportunity to test the voltage on the battery when the warning light was on (12.9v) and when the warning light went out (14.5v) so therefore the alternator does not charge from cold for a few mins....and then kicks in with a decent charge rate...
Reason for changing the battery is that I had an almost complete electrical power loss on the way home from work the other day, battery gave all the appearence of being flat and restarted with a jump from a mate's motor...
I reckon either the alternator is on its way out (sound likely?) or I have some sort of dodgy earth somewhere. The earth lead from the battery seems to go off somewhere into the loom or something. Does anyone know where it secures to the chassis? I'd like to check it.
Any other ideas? Or shall I bite the bullet and replace the alternator?