DC-DC Converter

📖 YOUCANIC Automotive Glossary

The DC-DC converter replaces the alternator in hybrids and EVs, stepping down 200-800V to 12V to charge the auxiliary battery and power all standard electrical systems. Without it, the 12V battery drains even with a fully charged drive battery. Symptoms mimic a failing alternator: dead 12V battery, dim lights, inability to power up.

Diagnose by checking 12V system voltage in READY mode — should read 13.5-14.5V. The YOUCANIC UCAN-II reads hybrid system codes including DC-DC converter faults.