DC/DC Junction Box

WARNING: This page is about a different car, the 2011 Nissan Leaf. However, it is still accessible from the selected car via links, so may be relevant.

The DC/DC junction box integrates a DC/DC converter to supply electric power to the 12 V power system and charge the 12V battery in addition to distributing high voltage power from the Li-ion battery to systems.

The DC/DC junction box has a normal charge relay and a quick charge relay so that the circuits are changed over according to the charge mode.

The DC/DC junction box has an internal cooling fin used to cool the DC/DC converter by water cooling.

Fig 1: Identifying DC/DC Junction Box

Courtesy of NISSAN MOTOR CO., U.S.A.

DC/DC CONVERTER

The DC/DC converter steps down the high voltage DC current of the Li-ion battery to a 12 V DC current, which is used to supply power to the 12 V electrical system and charge the 12V battery. In addition, the DC/DC converter changes the output voltage according to VCM signals so that appropriate voltage is supplied depending on the vehicle condition.