where is this center pin that you speak of?
Right down inside where the above pic says "510 internal
thread", down inside there is the center pin.
The center pin is the positive side of the battery, and the outside metal is the negative side of the battery;
When those two side are touching one another, the battery is shorted out and bad things happen.
The electonics inside the battery are supposed to at least prevent the bad things from happening.
To upload pics, use the tab for "From UR", not the default tab "From Computer". You probably have to have enough posts like 15 posts before you can upload pics.