I was wondering how could I hold a lot of charge inside, for example, a ball. I thought by wrapping it in an isolant and using a hole with a semiconductor to charge it without letting anything out. But them it also could blow apart by the repulsive force of itself. Therefore, I got curious of how to calculate the pressure necessary to hold it still. I thought about considering it a bunch of infinitesimal balls with infinitesimal charge but I don't now enough calculus yet to put it in a equation.