It's a Julet connector. I can't say that I've ever seen one for sale. Even if you could find one, it would be moulded to the wire, so you'd need to solder the wires.
People are always asking about battery connectors. You don't need them. They're only a source of trouble. It's much better to cut off any connectors and solder the wires directly. That's quicker, easier, cheaper and more reliable. Why would you want anything else?
