Small cells and industrial plants are different. Charging some cells produces an off-gas of hydrogen, which requires you to change the air in the room with the cells, which means fans. You also have to ensure that the temperature of the room stays within certain bounds, which could mean bigger fans.

In terms of cells, batteries don't really smell like anything I find. However, you need to top up the water levels which requires distilled or deionized water. Will they be doing water treatment on site?

All that being said, there's more than enough room for a discussion about concerns. These yokels jumped right to death threats instead of progress. I wish nothing but rolling blackouts and a lack of jobs for them in the future.