Suit protects him thousands of volts of electricity, and enough to seriously harm Croc.

A blinding flare of light burst from the cable end as thousands of volts of electricity crackled through his body.

Batman held the cable steady as they fell, insulated from the current by his suit. Croc roared, trying to say something, but the muscles in his jaw spasmed so violently that the sound became a long uh-uh-uh-uh that ended when both of them crashed onto one of the pipes, and then slid off to splash into the puddle that had collected beneath them