Electrical Engineering Expert Testimony Found Reliable In Lithium Battery Fire Case

    Electrical Engineering Expert

    Court: United States District Court for the District of Central California
    Jurisdiction: Federal
    Case Name: Glassman v. Home Depot USA, Inc.
    Citation: 2018 U.S. Dist. LEXIS 122842


    In this product liability case, the plaintiffs alleged that a lithium-ion battery manufactured by the defendants caused a fire in their garage. The plaintiff’s hired an electrical engineering expert to opine on causation. The defendants moved to preclude the expert’s testimony, and they argued that because the plaintiffs’ entire case depended on White’s testimony, they filed for summary judgment in the case.

    The Expert

    The electrical engineer had over 30 years of experience working as a fire causation expert. He had also worked on a number of cases involving lithium-ion batteries over the previous 10 years.

    The electrical engineering expert worked with a fire origin expert who opined that the fire had initiated from a workbench of the garage. After the fire origin expert eliminated some potential causes (arson, smoking, etc.), the electrical engineering expert ran an arc mapping survey to determine the cause of the fire. Arc mapping is a tool documented in the NFPA 921, which is the National Fire Protection Association guide for proper practices and procedures to determine the cause and origin of a fire. This survey showed that the fire had originated from a battery kept in a charger, which he found out later was not made by the defendants.

    The electrical engineering expert then took two batteries from the floor near a workbench and ran CT scans on them. This procedure was supported as proper for determining the origin of fire from a battery by peer-reviewed journal citations. There he found that there was ‘thermal runaway’ in one of the batteries manufactured by the Defendants which, according to him, was the cause of the fire. This was reported in his Supplemental Report.


    The court expressed concerns with the electrical engineering expert’s conduct in changing his methodology immediately upon finding out that the defendants had not manufactured the battery determined as the cause of the fire. Moreover, the expert chose to scan only two batteries, which he knew were the defendants’ products, despite the defendants’ claims that there were other batteries in the vicinity.

    The court noted that though the expert’s conclusions and the timing of his supplemental report were in question, he had used evidence to support his methodology. The court cited Schlesinger v. United States, 898 F. Supp. 2d 489, 505 (E.D.N.Y. 2012) (“The decision not to follow the methodology set forth in NFPA 921, as well as other purported flaws in the Russo methodology—e.g., the failure to rule out other possible causes—goes to the weight of the evidence, not its admissibility.”) The court found the expert’s methodology reliable enough that it was not rendered as “junk science”. The court further noted that “The interests of justice favor leaving difficult issues in [*15]  the hands of the jury and relying on the safeguards of the adversary system—'[v]igorous cross-examination, presentation of contrary evidence, and careful instruction on the burden of proof’—to ‘attack[ ] shaky but admissible evidence….'”, citing Wendell 858 F.3d at 1237-38 (citing Daubert, 509 U.S. at 596).


    The court declared the testimony of the plaintiffs’ electrical engineering expert admissible and denied the defendants’ motion for a summary trial. It was determined that shakiness in an electrical engineering expert’s opinion does not make it inadmissible, as the opinion can be rigorously challenged during cross-examination in front of a jury.