[fu86]

I am not sure about that (biggest battery in the world). This looks like a battery "pack" (an array of batteries connected in parallel/series). This looks like just a marketing thing to me, because there is nothing new or special about it. Just "the biggest".

Germany is also working on big batteries for years, but with a completely different strategy. A redox-flow battery with polymers and saline solution (https://www.nature.com/articles/nature18909) Here is a recent german article about it (http://www.spiegel.de/wissenschaft/technik/brine4power-so-fu...)

This kind of batteries will hold 700 MWh.

[quesera]

A battery is an array of cells.

The usage of "battery" is completely proper in this case, and it can be argued that the common usage is improper.

("prescriptive" vs "descriptive" rejoinder omitted for brevity)

[frandroid]

Do you understand that the word "battery" means "array"?

[qu1mby]

Or the more polite variation: "'battery' actually means 'array', so it's being used appropriately in this case"