The powertrain cooling loop
Cooling the motor and inverter, which run far hotter than the battery.
You'll learn
- Explain the powertrain cooling loop at engineering level
- Read the numbers that define the behaviour
- Apply the idea to a real vehicle
Overview
Motors and inverters tolerate — and generate — far more heat than a battery, so their loop is deliberately kept separate and runs at a higher temperature.
In depth
Cooling system explorer
Powertrain cooling loop explorer
Explore the motor and inverter cooling circuit.
Hot day driving: High ambient heat load; chiller and radiator both working, fan at high duty. Pump duty 85%
Battery loop vs powertrain loop
| Battery loop | Powertrain loop | |
|---|---|---|
| Typical operating temperature | 15–35 °C | 40–65 °C |
| Sensitivity to overshoot | Very high — ageing risk | Moderate — power derating |
| Radiator effectiveness | Poor in hot ambient | Good even in hot ambient |
Key takeaways
Remember this
- The powertrain loop runs 20–30 °C hotter than the battery loop.
- That higher temperature keeps its radiator effective in hot weather.
- Separating the loops avoids one component's heat load compromising another's target.
Mark this lesson complete
Confirm you've read through and we'll count it toward your progress.
Previous
Anatomy of the battery cooling loop
Up next
Valves: the traffic controllers of the thermal system
Was this lesson helpful?
Rate this lesson