RobotStudio event

Battery management of ABB IRB2400L with S4Cplus controller (robot of about 10 years)

Hello,

We have an ABB IRB2400L robot in our robotics lab in the university. This means that the robot is not working in a production chain and may be off for a week. The robot has about 10 years and I had to replace some batteries. The question is: What is the good way to have the controller and the batteries as "healthy" as possible? Should I leave the controller turned/on 24 hours? Is there any recomendation about that? 
Bear in mind the robot is used for practices with students, which means it can be working about 4 hours per week. With "working" I mean loading programs, moving the robot with the teach pendant and so on. The rest of the time I dont know if I should leave it on or simply turn off the controller.

Best regards,

-Mario