Ashley doesn't learn does he, unfortunately for him we're all learning to not pay much attention (sorry Ash - but you do pipe up too often without facts, don't take offense at this).
The balancing plug on the Trakpower is by a small bullet connector. I have no means of measuring it, but if you want to see
http://www.trakpower.com/ and click on "TP4900 2cell", this brings up a picture including the balancing socket.
ofcause the + & - is by conventional sized corallys - im using LRP plugs and they're snug, so that is good.
Chris