A rechargeable battery includes: an electrode assembly configured to perform charging and discharging; a case enclosing the electrode assembly; a cap plate coupled to an opening of the case; an electrode terminal engaging a terminal hole of the cap plate; and an insulator between the cap plate and the electrode terminal, wherein the insulator comprises: a fluid receiving recess at a side of the electrode terminal to receive fluid, and an outlet extending through the insulator from the fluid receiving recess to discharge the received fluid.