There may be a few reasons why your batteries are draining faster than expected.
First, check to make sure the cable on the inside of the lock is securely fastened. To do this, you will need to remove the battery cover from your lock, remove the battery and then unscrew the two mounting screws and dismantle the interior side of the lock. Check that the cable is snugly fit into the socket on the interior side of the lock.
You should also check your door prep and alignment. If your deadbolt jams when trying to lock the door, this could cause your batteries to drain quickly. Check out this video for help with your door alignment.
Recommended Batteries for Yale Smart and Digital Locks