10pairs 1S 2 pin Molex 51005 51006 2.0mm Pitch Chage Cable Male and Female Lead Plug Connector for 1S Lipo Battery Charging Drone Syma

That connector is typically on 1s batteries. Don’t think I’ve ever seen one on a 2s, but it definitely is in your case. Here’s a link to the type of connectors that you could splice into a banana or whatever https://a.co/d/0hOjALgT Edit: forgot the link