Step 6 – Thermal Management System

Install a dedicated liquid cooling loop for the battery pack, motor, and inverter. Proper thermal management extends component lifespan from ~1000 cycles to 2000+ cycles and maintains performance in all conditions.

Procedure

1. Design cooling loop: pump → battery cold plate → inverter → motor → radiator
2. Select automotive-grade EV coolant pump (Pierburg or Bosch)
3. Install compact aluminium radiator in original engine bay position
4. Fabricate aluminium cold plates for battery module bases
5. Mount coolant pump on firewall — vibration isolated
6. Use silicone hoses rated to 150°C — avoid standard rubber
7. Install coolant expansion tank in accessible location
8. Route coolant pipes away from HV wiring and sharp edges
9. Install coolant temperature sensors at inlet and outlet of each component
10. Connect sensors to BMS/VCU for thermal monitoring and fan control
11. Fill with 50/50 water-glycol OAT coolant mixture
12. Bleed system and check for leaks at all joints

Safety Warnings

1. Never use tap water in EV cooling loops — causes electrolytic corrosion
2. Coolant leaks near HV components are extremely dangerous
3. Maintain coolant temperature below 150°C maximum

Pro tip

Air-cooled motors can eliminate the cooling loop for budget builds. However, for sustained performance driving, liquid cooling is strongly recommended for both battery and motor longevity.