> Grid batteries have slightly different requirements compared to EV batteries. Weight/volume doesn't matter. Charge speed isn't a priority. [...] I have the i

> Grid batteries have slightly different requirements compared to EV batteries. Weight/volume doesn't matter. Charge speed isn't a priority. [...] I have the impression that Tesla tweaks the chemistry depending on the application. The cells used for power wall and grid storage might be slightly different to take advantage of those differences. While weight/volume isn't important itself, reducing the weight/volume per kWh will also tend to reduce the cost per kWh since you're using less materials. There are storage solutions that go further in taking advantage of the points you mention, such as flow batteries, but in that case I think it can be expensive to get high power output. The article mentions that price per kW is also important. With batteries you automatically get more watts the more watt-hours you add, which is useful in many cases.