[nl]

There's plenty of capacity for grid connected batteries.

For one thing they can use a bunch of tech that doesn't work well in cars (flow batteries for example).

And the price goes down because the primary constraint is production capacity. More demand means more factories mean cheaper prices. See eg the growth in manufacturing capacity in batteries and their price decreasing:

    If you look at 2008, there was 6GWh of battery manufacturing in the world and 97% of it was in China.
    In 2019, there was around 365GWh worldwide, split into: China (75%), US (9%), South Korea (7%) Europe (5%)
    By 2023 we estimate there will be 1,230GWh worldwide: China (65%), Europe (10%), US (10%) and rest of the world (15%).

https://www.energy-storage.news/behind-the-numbers-the-rapid...