How It Works: Battery Thermal Management System with a Liquid-Cooled Condenser (L-CON BTMS)
Lithium-ion battery cells used in electric vehicles (EVs) are highly sensitive to temperature, impacting various aspects of their performance, range, efficiency, charge time, and cycle life. Cold temperatures cause a decrease in capacity and power, with extreme cold potentially leading to irreversible damage. Conversely, high temperatures result in capacity loss, power reduction, and risk of damage or even explosion. To address these temperature-related challenges, a battery thermal management system (BTMS) is crucial. The BTMS ensures that the battery pack is maintained within the optimal temperature range of 20°C to 45°C, regardless of ambient temperature. This system plays a crucial role in preserving the battery’s performance and longevity.
In the context of commercial EVs, particularly off-highway and specialty vehicles, there are additional challenges to consider. These vehicles themselves often have limited space available for accommodating a BTMS. Additionally, they frequently operate in dirty environments with high levels of particulates or debris. These factors further complicate the design and implementation of effective thermal management systems. To overcome these challenges, Modine has developed an innovative solution – Battery Thermal Management System with a Liquid-Cooled Condenser (L-CON BTMS). This advanced system efficiently regulates the temperature of battery packs, even in tight spaces within the vehicle and harsh operating environments.
To the left is a comprehensive schematic of the L-CON BTMS, showcasing its two-stage heating and cooling system for optimized operation:
Heating: In cold ambient conditions, the L-CON BTMS incorporates a heating mechanism to warm the battery pack. This is essential to facilitate charging/pre-conditioning and achieve the ideal temperature range for optimal performance. The L-CON BTMS heating loop is equipped with a high voltage (HV) electric heater, which effectively warms the coolant to the desired set point.
Active Cooling: The L-CON BTMS incorporates an active cooling system that utilizes a liquid-cooled condenser to control the temperature of the electric vehicle (EV) battery pack. When the ambient temperature exceeds the battery pack’s temperature, the active cooling loop is activated, engaging a refrigeration circuit. Within this system, heat from the battery coolant loop is transferred to a refrigerant through a chiller (shown in green in the schematic). The refrigerant then passes through the liquid condenser (L-CON), which is cooled by the coolant in the radiator coolant loop (shown in blue in the schematic). This coolant, in turn, is further cooled by directing air through a radiator (shown in yellow in the schematic), dissipating heat into the ambient air. This radiator coolant loop can be used to cool the power electronics as well, effectively cooling both the L-CON and power electronics components. Replacing an air-cooled condenser with a liquid-cooled condenser allows for a smaller footprint for the L-CON BTMS in comparison to the A-CON BTMS, which makes installation in confined spaces anywhere on the chassis an advantage for L-CON BTMS.
Additionally, the L-CON BTMS integrates an advanced master control system. This master smart control system leverages the temperature readings from the battery pack or coolant to determine the appropriate mode of operation for meeting the heating and cooling requirements of the batteries. It intelligently utilizes the coolant temperature sensor to precisely adjust the flow of coolant, ensuring efficient and effective thermal management of the battery pack.
The L-CON BTMS offers a compact design that optimizes space utilization in commercial EVs while maintaining functionality and performance. It excels in harsh and dirty environments, resistant to clogging caused by poor air quality or high particulate levels. This reliability ensures efficient heat transfer and thermal management performance over an extended period of time. Modine’s purpose-built L-CON BTMS is designed to meet the specific demands of heavy-duty vehicle platforms, ensuring that commercial EV batteries remain within optimal temperature ranges in all operating conditions, whether it is hot summer afternoons or icy winter mornings.