I think what needs to be considered is the makeup of the...

I think what needs to be considered is the makeup of the battery. The most common form of car battery has been the Lithium NCM (nickel cobalt manganese) with cobalt being necessary for stability, but its expense has been significant in searching for other form of anodes, including those that don't have any cobalt.

From what I can gather from the releases the tungsten battery is a Lithium Tungsten/Niobium battery. Niobium is sometimes referred to as "rare earth" although some other sources say it is not. The rare sometimes doesn't mean scarce either, just refers to properties. The availability of niobium may be a limiting factor on the production of the batteries but without knowing how much is needed the effects can't be determined. There are niobium mines in Australia, wouldn't it be great if the EQR deposits also included niobium!

Anyway, agree with Plonka, EQR good investment without batteries, great investment if they take off.