This case involves a class action that was initiated in response to a line of defective and dangerous children’s toys. It is alleged that the toys, which contained a large battery pack along with motorized components, posed a significant fire hazard while in use and while charging. It was believed that a circuit board on these toys had a propensity to over-heat, causing spontaneous ignition of the toy’s internal electronic components. This has caused the toys to emit smoke, fumes, sparks, and flames in several separate instances, some of which have resulted in building fires and extensive injuries. It is alleged that the circuity contained in these toys was negligently and dangerously designed, and that owners of the toys were not warned of the potential for fire. A batteries expert witness was sought to opine on this issue.