If an electronic component is activated by a lithium metal battery, the electronic component is regarded as the main component and the lithium metal battery will be an auxiliary component. From common practice, this unit will be classified as UN 3091 Lithium metal batteries contained in equipment and PI 970 will apply.
If the lithium metal battery is the main component and the electronic device is subsidiary, thence the product will be regarded as a type of battery and assigned to UN 3090 Lithium metal batteries and PI 968 will apply.
Without inspecting the actual product, a common observation will tend to indicate that the product is a type of electronic equipment containing lithium metal batteries. There is no reference document to substantiate this definition. Common practice applies.