Batman (Earth-43)

The ears are so huge in this version.

What would Batman be like as a vampire? We have the alternate reality Earth-43 version of Batman to answer that!
Batman and Dracula: Red Rain
Batman discovered Dracula was alive and in Gotham. He had the vampire Tanya remove some of his blood thus making him a vampire, but allowed him to retain his humanity. Batman tricked Dracula's minions to attack the Batcave. When Bats destroyed the roof, the vampires were exposed to sunlight thus killing them. However, this was a Pyrrhic victory since Dracula drained the rest of Batman's blood. This turn Batman to a true vampire. Batman assured Alfred that, while Bruce Wayne is dead, Batman will continue to live on endlessly.
Bloodstorm
The Joker had taken control of the rest of Dracula's minions, who had become near-mindless monsters obsessed getting with their next meal. Batman, a werecat Catwoman, Alfred, Commissioner Gordon and several vampire hunting members of the Gotham PD teamed up to fight the vampires. During the climactic battle with the vampires, Catwoman was killed. Batman (enraged) drained the Joker's blood. Horrified by this deed, he stakes the Joker (to make sure he can't become a vampire) and himself (with the help of Gordon and Alfred).
Crimson Mist
It turns out Alfred and Gordon didn't cut off Batman's head. As such when Gordon removes the stake from his chest, Batman is restored. Why the Joker doesn't come back isn't explained. Driving mad by a longing for blood and his body decaying, he killed his old enemies including the Scarecrow, Amygdala, Black Mask, Riddle, Poison Ivy and so on. Eventually, Killer Croc and Two-Face were the only remaining villains. They team up with Alfred Pennyworth and Commissioner Gordon to kill Batman. After finding Bats hiding in the ruins of Wayne Manor, Alfred decided to set up bombs that will force Batman into the sunlight. During the fight, the villains are killed. Alfred allowed Batman to kill him so Batman can have the strength to save Gordon. Batman convinced Gordon to trigger the trap. After Gordon did so, Batman walked into the sunlight thus finally finding peace.
Powers and Abilities
Batman had vampire powers. This includes super strength, immortality (unless killed by one of his weaknesses), flight and the ability to turn into mist. Stabbing him with a stake simply comatose him as oppose to kill him. However, he has the vampire weaknesses: holy water, crosses, garlic and sunlight. When he sustained by blood, he is immune to all the weaknesses except for sunlight. While they have been dulled, he retained the skills he had as Batman.
References:
http://en.wikipedia.org/wiki/Batman_&_Dracula:_Red_Rain
http://dc.wikia.com/wiki/Bruce_Wayne_(Earth-43)
http://batman.wikia.com/wiki/Bat-Man_(Earth-43)