Pros
Able to learn from experienced people in the battery industry from the science to manufacturing. This was a start-up like atmosphere while I was there. This is the place to go if you want to develop a career as your role will evolve with the company.
Management is highly competent, some of the most competent management I have experienced in my career. They are effective, motivated to succeed, communicate well, and are fair minded.
Ownership cares about its employees and will do what they can to help their employees, plus, they provide snacks!
Paid time off is generous (18 days a year) and they do encourage you to use it.
Very professional and European style business atmosphere (polite, professional dress, work-life balance).
Cons
It is still a start-up so there can be volatility in job security from that.
The only benefit they pay for is healthcare (but they have a whole assortment of benefits from dental, vision, disability, 401k, and others, but those are all financed by you at this time). They pay about half for an individual, but the deal is better if you have a family plan as they pick up a large part of that. This is a start-up, so money is still tight, but as they progress, benefits should get better.
While the above is true for professionals, the technician point of view may be different.