Hi guys,
if I don't install nvidia drivers, are the noveau drivers on? I want to use integrated graphics in order to get a better battery life. How I can be sure to use the correct card?

In most cases the noveau is fine (i've used them both).
But I have no idea if one of these drivers is 'better' for a laptop's battery.
And I have no idea which driver is compatible/'optimal' with your card.
Give the forum more details and look at some relevant posts and someone who has savvy (not me) with cards/graphics will help you out.