Pros
Good place to start, interesting work with a lot of potential to learn new things. Management tends to be hands off for the most part, schedule is pretty flexible.
Cons
Battelle has so many problems. The compensation is mediocre and in some cases unfairly low. Benefits are atrocious. If you are a researcher, scientist technician, etc, upper management has no idea what you do and they don't understand it at all. Leads to a lot of problems when it comes to staffing and budgets. The real problem though is the amount of favoritism and politics that goes on. I have watched so many deserving people get passed over for someone who got in with the right people despite having inferior knowledge and expertise. You will not get promoted unless you know someone. They will decide pretty quickly if you're in the in crowd or not and if you, like most, aren't then just get your experience and leave because it's not worth working for a company that doesn't respect you as an employee.