Battery drains in half hour.

[MalcQV]

The alternator has been checked?

[martb]

I Have had the bonnet open while carnking with someone else looking, but ill do it agin and have a look myself.

I dont think its the alternator as theres no power issues/dimming etc when im driving and its putting charge back into the battery.

[ini]

If your battery is ok and it is draining that fast, it must be a pump or motor running on.

Otherwise something is getting very hot.

Your starter will not crank unless the voltage is above a specified minimum, and the car will not be fueled unless the starter is turning above a certain RPM.