Tesla’s first battery pack design for the Model S was defective and prone to coolant leaks, leading to a fire,media Business Insider reported. The report describes how the company appears to be cutting back on this particular part of the Model S, which was scrambling to ship when it began to establish itself as a mass-market electric car maker in mid-2012.
The new report comes as Tesla ranks last in JD Power’s annual new car quality study. The move comes after the National Highway Traffic Safety Administration (NHTSA) announced an investigation into early Model S touchscreen malfunctions.
According to Business Insider, the Model S battery pack had two specific problems, and the company spoke to three former employees and reviewed internal emails and documents. First, a third-party testcompany told Tesla that the aluminum used by the company at the end of the battery pack cooling coil softened with cracks and pinholes, which could lead to coolant leaks. On top of that, the connectors at the end of the coil are not perfect, and one employee described them as “shaky.” This also makes these coil packages prone to leakage.
According to the media report, Tesla “continued to find leaking coils at various stages of production until the end of 2012”. The issue was referred to senior management, but the cars were eventually sold.
Tesla has always insisted that its cars are the safest in the world, and self-reports annual vehicle fire statistics far lower than gasoline-powered cars. However, the company has made a number of changes to model S over the years to reduce the risk of fire. The company released a software update in 2013 that allowed the Model S to increase ground clearance at high speeds to reduce the chance of debris punctured the battery pack and added more physical protection to the new offline battery pack, all after NHTSA investigated multiple fires. (The agency closed its investigation in 2014.) Tesla also released a software update in 2016 to “provide additional security during charging” after a Model S caught fire in Norway.