Projects
Please visit the Portfolio section for additional pictures of the project described below.
Extreme Temperature Validation: EV Bronco’s Battery and Cabin Cooling
The EV Bronco’s thermal management system performed effectively in extreme hot-weather testing in Death Valley. Using a water-to-refrigerant heat exchanger (chiller) for battery cooling and an air-to-refrigerant heat exchanger for cabin cooling, the system maintained safe uniform battery temperatures during charging and a rigorous 16-mile drive with a 5,000-foot elevation gain at 40°C. This testing validated the thermal management system's mechanical components, including several in-house designs, and provided insights for future control system improvements.
EV Bronco Thermal Management in Cold Weather Testing
The EV Bronco's thermal management system, tested in Lake Tahoe’s freezing conditions, uses a 50-50 ethylene glycol and water mix for both heating and cooling. In cold weather, this fluid is heated by a high-voltage electric heater and circulated through chill plates, maintaining uniform battery temperatures within 5°C and keeping them above the derating threshold. The same fluid and heater also heat the cabin, ensuring consistent performance and effective temperature control for both battery and cabin in extreme cold.
Internal Manifolding in Chillplates for Optimized Battery Cooling
In the EV Bronco, space limitations required vertically stacking the battery packs onto chill plates with internal manifolding, eliminating the need for external plumbing. The three-level design featured varying flow obstructions inside the chillplate flow path, with the top level having the largest obstruction, reducing at each subsequent level. This internal manifolding ensured uniform fluid distribution for optimal battery cooling, validated through flow simulations, calculations, and experimental testing.
Chillplate Design Validation and Production Transition
A liquid-cooled chill plate was designed to maintain the temperature of VDA-355 battery modules using an ethylene glycol/water mix. The prototype featured a two-piece aluminum design bonded with structural epoxy and underwent mechanical tests—bend, twist, pressure, and thermal shock—to validate performance and structural integrity. For production, stir-welded chill plates with the same flow path were used, employing a different manufacturing method. Future versions will incorporate internal fins to enhance heat transfer and improve performance.
Integrated Thermal Management System
The chill plate alone couldn't achieve optimal thermal management, as the coolant's heat needed to be dissipated before re-entering. Air-cooled radiators were ineffective due to the small temperature difference with ambient. A refrigerant-to-liquid heat exchanger (chiller) cooled the coolant, while a high-voltage heater heated it for cold temperatures. A valve-directed coolant flow to the battery, cabin, or both, depending on cooling/heating needs. The same high-voltage AC compressor was used for both battery and cabin cooling, splitting refrigerant between the HVAC system and chiller, ensuring effective thermal management for Kindred EVs.
Preliminary HVAC Design for EVs
Conventional ICE vehicles use coolant to capture heat from the engine, dissipating it into the cabin through a heater core, while a belt-driven compressor handles cooling. In EVs, high-voltage heaters and compressors replace these components.
Initially designed for cabin heating and cooling, the system was later integrated to also manage battery heating and cooling. A Restomod HVAC unit, Mitsubishi High Voltage AC compressor, and Webasto High Voltage heater were used in a closed-loop system to regulate the temperature in the cabin.
