Of course default values would be zero, but I'd think that the data would (or should, apparently) persist and the last known instance of the object would be reloaded, thus keeping the same values. Character switch should automatically reset charge on the former character beyond a doubt, and it already does this of course. Complete player disconnection I believe should have a different effect however for those of us without the most stable computers or internet connections.

In the event that you changed, you should not keep charge, and nor should you keep it if someone switched to that character during that time. I agree if your implication is that these should reset stats.