Need a little advice with an electrics problem

[mong]

Hi all,
Im new to these forums but have lurked a bit in the past.
Ive got a problem with my P Reg k11, i was driving it today when all of a sudden it lost power and stalled (at a bloody roundabout). i couldnt get it started and had to push it off road. Anyhows, it wouldnt start at all so i got someone to come pick me up (green flag).
The first thing they did was put a power pack on the battery and it started straight away, when they removed the power pack it spluttered and stopped. He checked the voltage between the alternator and battery and it was fine...and said the alternator was o.k.
At this point they towed me home and said it was an "electrical fault" that should be easy to fix.
I was wondering if anybody on here could shed any light on the problem/point me in the right direction.
Thanks.

 

[Alienfish360]

is it turning over? Are you getting a spark?

If not it may be your ignition barrell

 

[mong]

Thx for the reply.
Yeah...all is fine if there is a power pack/someone jumping. The battery is on charge as we speak, im expecting it to start fine and get me to a garage if necessary. There seems to be something stopping the alternator getting power to the battery, the output of the alternator is spot on which is good i suppose.
Im struggling to understand whats wrong, im no expert with cars, the pickup bloke said that the alternator is fine but that there could be a loose connection somewhere between the alternator and the battery, ive checked the connections i can see which seem fine.