i have a digital dash and i dont get a volt reading until i rev it up to aboutt 3k if it dosnt go above this on a 10min drive the battery will go flat

it dosnt gennerate any charge untill its spun at a fast rate and from then on opperates fine

any ideas?

The dash volt meter is just a guide only.
Check at the battery and alternator for correct reading with a multi meter,
If found not to be chargeing at either of those points renew alternator with a new reconditioned one.

get brad to help you