According to several aspects of the present disclosure, a battery module housing cooling assembly is disclosed. The battery module housing cooling assembly can include an endwall including a first polymer plate and a second polymer plate that define a slot therebetween. At least one of the first polymer plate or the second polymer plate define a channel therein that is configured to receive a coolant fluid, and the slot is configured to receive an electrical connector. The battery module housing cooling assembly can also include a cooling plate defining a first connection port and a second connection port, wherein the first connection port and a second connection port are configured to provide the coolant fluid to the channel.