can i use L298N H bridge with 12v 7AH battery?
Yes, though at 2A you're at the top end of the L298N current limit. Expect excessive heating. You will have to manage your thermal environment appropriately.
You should consider a more capable driver with more current headroom and less heat problems. (Note: the L298N is a very old chip and uses old technology. It's not a good choice for modern drive systems and a more appropriate device should be investigated, for example the MC33931 as the first hit on google).