Battery electric-powered vehicles continue to gain market share. This technology shift from internal combustion engines to high-voltage (HV) batteries may require a different approach for many collision repair operations. Longstanding repair procedures may no longer align with the advancements incorporated in new vehicles. One such procedure that may require rethinking is how vehicle refinish paint is cured.
Thermal Insights
The elevated temperatures commonly used when force-drying an automotive refinish system have the potential to cause thermal damage to the HV battery. The possibility of the booth curing temperature being too high is something that technicians rarely, if ever, contemplated in the past. HV batteries that store the energy needed to propel electric vehicles are sensitive to extreme temperatures and may be irreversibly damaged or possibly even destroyed if the proper procedures are not followed. All vehicle repair plans should begin by referencing the OEM procedures and fully adhering to them for all phases of the repair. It is critical for the repairer to be fully informed of the necessary processes and precautions, not only to protect the vehicle battery, but to minimize the chance of a life-threatening explosion or fire.
Thermal Regulation
The vehicle’s battery temperature is moderated through the utilization of various battery thermal management system (BTMS) technologies, dependent on the manufacturer. These cooling and heating systems are designed to maintain the battery temperature within the optimal functioning range, contributing to the expected performance and lifespan of the battery cells. Electric and hybrid-electric vehicle repairs may often require disconnecting the power sources — disabling the active BTMS and rendering the HV battery unprotected from temperature extremes like those that occur when curing the paint in the booth. Even if the BTMS is functional, concerns for battery heat exposure remain, and the repairer must still follow the parameters provided by the OEM to prevent possible thermal damage to the battery system.
Master the Plan
Creating a refinishing plan to ensure the vehicle’s battery system is not damaged can be a simple and straightforward process. In basecoat/clearcoat refinish systems, clearcoat curing specifications will determine whether the refinish operation meets the parameters set by the vehicle manufacturer for preventing damage to the battery system. The drying and curing information in the clearcoat technical data sheets will provide this data.
Key Curing Concepts
When assessing the suitability of a selected paint system, it is important to understand key concepts related to force curing in a paint booth:
It is critical to consider these factors when planning the refinish procedure, as they are directly related to the time and temperature parameters that OEM guidelines will provide. After reviewing and understanding the parameters set by the OEM, there are often several paint product system selections that can be effective in reducing bake time, bake temperature, or both. Some clearcoat systems are designed specifically for low bake temperatures or ambient air-dry conditions. Others offer various bake times and temperatures depending on hardener and accelerator selections. It is important to fully review the clearcoat systems available and find the best fit for your situation.
