A heat exchanger for cooling oil, including a plurality of pan-shaped heat-transfer plates stacked onto one another to define alternating channels for coolant and oil, a mounting plate soldered on one side to a side of the stacked plates and adapted to mount on its opposite side to a separate component. The porator operates free of any concurrent connection to any external source of power. A plurality of wires are disposed on the top surface of the insulative housing, each wire defines a conductor electrically connected with the connecting portion and a metallic braiding layer surrounding the conductor. The data is aggregated and stored for the plurality of devices in memory. The first extension branch is coupled to the main branch.