An EV conversion kit is only as good as its weakest component. A undersized controller will choke your motor. A cheap BMS can take down your entire battery pack. A generic wiring harness will leave you stranded. Here's every part you actually need, what it does, and what it should cost — so you don't waste money on the wrong pieces.
10 Essential EV Conversion Components
| # | Component | Function | Typical Cost (CMVTE Factory Direct) | Must-Know |
|---|---|---|---|---|
| 1 | Electric Motor | Provides torque to the wheels | $800 - $4,500 | PMSM AC motors are the modern standard. Rated kW > peak kW for real-world use. |
| 2 | Motor Controller | Converts DC battery power to AC for the motor; controls speed and torque | $600 - $3,200 | Must match motor voltage and phase amps. FOC controllers give smooth throttle response. |
| 3 | Battery Pack | Stores energy; determines range and power output | $2,000 - $10,000+ | LFP is safest and longest-lasting. NMC for higher energy density. View CMVTE battery options → |
| 4 | Battery Management System | Monitors cell voltage, temperature; balances cells; protects against overcharge/over-discharge | $200 - $600 | Non-negotiable for lithium packs. A good BMS with CAN bus is worth the extra cost. |
| 5 | DC-DC Converter | Steps HV pack voltage down to 12V for lights, horn, ECU, accessories | $150 - $500 | Size it for your accessory load. 1 kW minimum for most passenger cars. |
| 6 | Onboard Charger | Converts AC grid power to DC to charge the pack | $300 - $1,200 | 3.3 kW is standard for overnight charging. 6.6 kW for faster top-ups. View chargers → |
| 7 | Adapter Plate & Coupler | Connects motor to the original transmission | $200 - $800 | Vehicle-specific. CMVTE offers CNC adapter plates for popular models. |
| 8 | HV Wiring & Contactors | Main battery cables, pre-charge circuit, main contactor, fuse holder | $200 - $600 | Undersized cables cause voltage drop and heat. Use 2/0 AWG for most builds. |
| 9 | Cooling System | Radiator, pump, hoses, reservoir for motor/controller/battery thermal management | $300 - $1,200 | Air cooling works for <15 kW. Liquid cooling required above that. View cooling → |
| 10 | Throttle Pedal & Display | Driver input + dashboard instrumentation (SOC, speed, warnings) | $200 - $700 | Hall-effect pedals are more reliable than potentiometer types. |
Total Budget by Build Type
| Build Level | Motor Power | Battery Size | Component Cost (CMVTE) | Best For |
|---|---|---|---|---|
| Budget | 10-15 kW | 15-20 kWh LFP | $4,000 - $7,000 | City car, short commute, light vehicle |
| Standard (Recommended) | 25-30 kW | 25-35 kWh LFP | $8,000 - $14,000 | Daily driver, mixed driving |
| Performance | 40-60 kW | 35-50 kWh NMC | $15,000 - $25,000 | Highway, towing, performance builds |
Prices exclude donor vehicle, labor, and shipping. All components factory-direct from CMVTE.
How These Parts Work Together
Power flows: Battery → Contactor → Controller → Motor → Gearbox → Wheels
Support systems: BMS monitors battery safety → DC-DC powers 12V loads → Charger refills the pack → Cooling keeps everything at safe temperatures → Display tells you what's happening
The key to a reliable build: all components must speak the same language. CMVTE's motor, controller, BMS, and display are all CAN bus compatible — they communicate in real-time, giving you smooth throttle response, accurate SOC readings, and system-wide fault detection.
What's NOT in a Typical Kit (Common Hidden Costs)
- Battery enclosure / box — often custom-fabricated for your vehicle
- HV cable lugs and crimping tool — specific to 2/0 or 4/0 cable
- Coolant and hoses — generic parts, but add up
- Adapter plate — vehicle-specific; included in CMVTE's conversion kits for supported models
- Installation labor — 2-5 days for a shop, 1-3 weeks for a first-time DIYer
Why CMVTE Components Are Different
- Factory-direct — no distributor markup on motors, controllers, or battery packs
- Pre-matched systems — controller shipped with motor-specific firmware, CAN bus mapping done at the factory
- Tested before shipping — every motor and controller pair is bench-tested for power output and communication
- Global support — engineering team available via WhatsApp during your build, not just email tickets
Build Your Kit
Tell us your vehicle, target range, and budget. We'll send a complete BOM with component recommendations and a single guaranteed price — no hidden fees, no upselling.
WhatsApp / Phone: +86 181 2358 8272
Email: [email protected]
Mention "Kit Builder" so our team knows exactly what you need.
