The DC-DC converter is often the last thing people think about in an EV conversion, but it's critical. It steps down your high-voltage traction battery (96V-384V) to 12V for lights, ECU, infotainment, windows, and cooling fans. Pick the wrong one and you'll get flickering lights, random shutdowns, or a dead 12V system mid-drive. Here's how to choose the right CMVTE unit for your premium build.
What a DC-DC Converter Does
Your EV's main battery runs at high voltage (96V-384V). Your car's original electronics all run on 12V. The DC-DC converter replaces the alternator — it takes HV power and delivers regulated 12V to the accessory battery and loads. Without it, your lights, horn, wipers, dashboard, and ECU won't work.
CMVTE DC-DC Converter Options
| Model | Input Voltage | Output | Power | Efficiency | Cooling | IP Rating | Size | Price |
|---|---|---|---|---|---|---|---|---|
| CMVTE DCDC-1.2kW | 96-180V DC | 13.8V / 87A | 1.2 kW | 92% | Passive (fanless) | IP67 | 220×150×70 mm | $350-$500 |
| CMVTE DCDC-2.0kW | 96-384V DC | 13.8V / 145A | 2.0 kW | 94% | Active fan | IP67 | 260×170×80 mm | $500-$700 |
| CMVTE DCDC-3.0kW | 144-450V DC | 13.8V / 217A | 3.0 kW | 95% | Active fan + heatsink | IP6K9K | 300×190×85 mm | $700-$950 |
All models are fully isolated, with CAN bus communication, over-voltage protection, over-current protection, and thermal shutdown. They replace a standard alternator with no belt, no pulley, no mechanical wear.
Which One Do You Need?
| Vehicle Type | 12V Load Estimate | Recommended Model | Why |
|---|---|---|---|
| Small classic (MGB, Spitfire, Fiat 500) | 400-800W | DCDC-1.2kW | Minimal electronics, no AC, low fan draw |
| Saloon or GT car (Jaguar, Mercedes W123, BMW E30) | 800-1,500W | DCDC-2.0kW | Power seats, AC blower, stereo, multiple fans |
| Full-feature build (AC, audio, screens, aux heater) | 1,500-2,500W | DCDC-3.0kW | High amp draw from multiple systems |
Installation Notes for Classic Cars
- Mount: In the engine bay or under the chassis, away from direct road spray. All CMVTE units are IP67-rated for splash resistance.
- Wiring: Use 4 AWG or thicker for the 12V output if you're running high loads. Fuse both the HV input and 12V output within 300 mm of the converter.
- Ground: Connect the 12V negative directly to the chassis ground, not through the HV battery negative.
- CAN bus: Wire to your motor controller's CAN network for real-time voltage and temperature monitoring on the dashboard display.
- Pre-charge: CMVTE units have an internal pre-charge circuit. No external pre-charge resistor needed.
DC-DC Converter Checklist
- Add up all 12V loads (lights + fans + ECU + stereo + AC = ____W)
- Add 30% safety margin
- Match input voltage to your battery pack
- Choose CMVTE model above
- Install with proper fusing and chassis ground
Browse CMVTE DC-DC converters →
Get a Converter Recommendation
Tell us your battery voltage and total 12V accessory load. We'll recommend the exact CMVTE model, wiring diagram, and mounting bracket for your classic.
WhatsApp / Phone: +86 181 2358 8272
Email: [email protected]
Mention "DC-DC" for a wiring diagram and quote by return email.
