My new Vauxhall Zafira life 1.6

I have just got a brand new Vauxhall Zafira life 1.6, everything was going great until I parked up the kerb outside a friends house. I had a full tank of petrol. I went inside and when I went back to the car it started but I could not rev it and then the battery light came on and it died on me. I gave it a few minutes and it started okay. Then it was fine and a few day's later I drove the kids to the seaside and it did the same again but after a few minutes it started fine. Has anyone got a clue what could be happening?

Thanks In Advance

Shez