Since the cold weather has started, i have noticed that the EB dosen't start charging until i give it a rev after startup. The voltmeter stays on the second bar (approx. 12V) and then after a rev, it flicks straight up to the second bar from the top (approx 15V judging by the markings).
My guess is the regulator but I don't know much about cars. what is it and is it difficult to replace, cause i would like to do it myself.

yep, you pegged it. it's the regulator. Whilst your at it, brushes a clean and the battery a charge.

If you do the regulator make sure you get the sliprings machined and the bearings checked otherwise worn sliprings very quickly stuff up a new regulator brushes