Internal fin shape is one of the biggest levers in EV battery cold plate design: it sets how evenly the cells are cooled and how much pressure drop the pump must overcome. This ToneCooling CFD study compares four fin designs to show the trade-off.
In EV battery thermal management, the internal channel geometry of the liquid cold plate is the single most impactful design variable. Different fin shapes create different flow patterns, turbulence levels, and heat transfer coefficients — directly affecting cell temperature uniformity, maximum temperature, and pump power requirements.
This comprehensive CFD study compares four internal fin designs (conical, I-channel, L-channel, and diamond) fabricated from two materials (ADC12 die-cast aluminum and AL6063 extruded aluminum) under identical thermal boundary conditions.
Test Configuration
| Parameter | Value |
|---|---|
| Heat Sources | 6 modules, 122 × 62 mm each |
| Steady-State Power | 369W per module (2,214W total) |
| Peak Power (1 min pulse) | 1,228W per module (7,368W total) |
| Coolant | 50% ethylene glycol at 65°C inlet |
| Flow Rate | 15 L/min |
| Max Allowed Flow Resistance | 0.03 MPa |
| Max Allowed Surface Temp | 73°C |
Steady-State Results: 4 Fin Designs Compared
| Design | TC1 (°C) | TC2 | TC3 | TC4 | TC5 | TC6 | Max (°C) |
|---|---|---|---|---|---|---|---|
| Conical (ADC12) | 80.5 | 81.2 | 79.9 | 80.3 | 81.7 | 81.1 | 81.7 |
| I-Channel (ADC12) | 78.3 | 77.8 | 76.4 | 79.2 | 80.6 | 80.8 | 80.8 |
| L-Channel (ADC12) | 78.1 | 77.5 | 76.6 | 77.8 | 78.4 | 78.7 | 78.7 |
| Diamond (ADC12) | 79.0 | 78.8 | 77.4 | 78.2 | 79.6 | 79.4 | 79.6 |
| Diamond (AL6063) | 76.3 | 76.2 | 74.8 | 75.7 | 77.1 | 76.8 | 77.1 |
The diamond-fin design in AL6063 material achieves the best thermal performance — maximum surface temperature of 77.1°C, which is 4.6°C lower than the conical design in ADC12. The AL6063 material advantage (201 W/m·K vs. 96 W/m·K thermal conductivity) accounts for approximately 2.5°C of this improvement.
Transient Peak Load Performance
When power surges from 369W to 1,228W per module for 1 minute (simulating rapid acceleration or fast charging), transient temperatures reveal each design’s thermal buffering capability:
| Design | Peak Max Temp (°C) | ΔT from Steady State |
|---|---|---|
| Conical (ADC12) | 114.6 | +32.9 |
| I-Channel (ADC12) | 103.7 | +22.9 |
| L-Channel (ADC12) | 103.4 | +24.7 |
| Diamond (ADC12) | 108.5 | +28.9 |
| Diamond (AL6063) | 101.0 | +23.9 |
The diamond-fin AL6063 design again leads with the lowest peak temperature (101.0°C) and the best transient response, benefiting from both the optimized flow geometry and the higher thermal conductivity of AL6063 aluminum.
Design Recommendation
For EV battery cold plates requiring both steady-state and transient thermal performance:
- Best overall: Diamond fin in AL6063 — lowest temperatures in both steady-state and transient conditions
- Best uniformity: L-channel in ADC12 — lowest temperature variation across 6 heat sources (2.1°C spread)
- Best cost-efficiency: I-channel in ADC12 — die-castable geometry with good thermal performance
- Not recommended: Conical in ADC12 — highest temperatures and poorest transient response
Frequently Asked Questions
Why does AL6063 outperform ADC12 in thermal simulation?
AL6063 has over twice the thermal conductivity of ADC12 (201 vs. 96 W/m·K). This allows heat to spread more effectively from the cell contact surface into the coolant channels, reducing peak surface temperatures by 2–3°C. The trade-off is that AL6063 requires CNC machining rather than die-casting.
What is the maximum power per module this cold plate can handle?
At 15 L/min with 50% glycol at 65°C inlet, the diamond-fin AL6063 design maintains safe temperatures up to approximately 500W steady-state per module. For higher power levels, ToneCooling can increase flow rate, reduce inlet temperature, or redesign channel geometry.
How is the diamond-fin channel manufactured?
Diamond-fin channels are CNC-machined into the cold plate body, then sealed with a brazed or friction-stir-welded cover plate. This process provides precise channel geometry control and excellent sealing integrity. ToneCooling offers both brazing (CAB) and FSW joining methods.
prototypes from 1 piece · PPAP Level 3 · ISO 9001 Certified
Related: EV Battery Cooling Solutions | Liquid Cold Plates | Design Guide
Related ToneCooling Resources
Industry References & Standards
Why Choose ToneCooling for Cold Plate CFD Thermal Analysis
Engineering review and prototype planning are based on the project requirements. Custom prototype lead time is normally 4–6 weeks after drawing approval and order confirmation; confirm the production schedule in the quotation.
Need a Custom Liquid Cold Plate?
ToneCooling engineers review your drawings and requirements and reply by email with next steps.
Last updated: 2026-10-02
Related guides
- What is a battery cold plate — types, design and integration
- Custom battery cold plates — EV and BESS projects
- Stamping and brazing for EV battery cold plates — high-volume construction
- EV battery cold plate design — thermal management and fast charging
