> "Tesla set fire to a Powerpack to test its safety features – the results are impressive"
This is cherrypicking to make a point. The batteries still contain chemicals which are toxic to life and environment. There will come a time when those batteries are "consumed" and the chemicals within them need to be dealt with in some safe manner. As far as I know, there's no battery technology with any side effects.
Tesla's batteries are well designed and engineered. Batteries before them have exploded, caused fires and loss of life and property. As long as the nuclear plant was also well designed I can say
"I set fire to a nuclear plant to test its safety features. The plant shut down automatically – the results are impressive"