I'm on an Admissions unit where the most acute go. We typically get 2-4 admits durring the day, split between 3 nurses. Can be more tho. Groups start at 8 and patients have 7 therapies/day, 3 with a psychologist, OT, or therapist, and 4 group therapies like "wellness", "Goals", or recreation therapy, etc.
Typically, if your charge, you won't be assigned to hold a group activity, which I love. Instead, you'll be doing assignments and, and dealing with transfers. At my hospital, charge gets a team of patients. However, we have a LPN who typically does meds.
On my unit, charge nurses get less patient contact and tend to have to hang in the office more than the non-charge RNs.
EDIT: I'm at a state psych hospital.