how to store

I have just brought my first sat nav a navman icn330. Tried out yesterday and it was excellent for the £90 I paid for it. My question is because I will not be using it constantly and don't want to leave it in the car should I

1. Turn the battery off on the screen.
2. Remove the memory card before storing.
3. Will any of the above mean that I will loose any addresses from my favourites.

Many thanks for any help.

Di