When does the potential difference between the two terminals of the battery be zero?

Question

I think it will be zero if the battery is consumed entirely or when the circuit is open.
I thought a lot but have no good answer, please help

Answer 1

Agree if the battery is dead BUT
If the circuit is open the voltage is whatever the battery was charged to.
If the circuit is "shot circuited", the terminals connected by a thick wire of zero resistance, the current becomes infinite and the voltage zero
V = i R
V = i (0) = 0

Answer 2

Ok, but is there a wire with no resistance.
And why we neglict the internal resistance of the battery (r)?