I think that blog talks about selling their batteries to other car manufacturers. But, to support your wider point, there's some reporting that the initial gri

I think that blog talks about selling their batteries to other car manufacturers. But, to support your wider point, there's some reporting that the initial grid BESS Megapack batteries had a test setup in the car park at Tesla and Elon was unaware they existed until they got mentioned to him in a meeting and someone pointed out the window to explain. He immediately wanted to shut that project down to focus on cars.