Looks like a Tamiya male which is sometimes called a 'standard' connector. The puzzling thing is the clip on the side, I've never seen one on the side like that. This one is typical, clip is in the middle.
http://www3.towerhobbies.com/cgi-bin...&I=LXNGB6&P=ML
They're not the greatest connector, tend to get sof t and melt at high current. I'd replace it with something more convienent to use.