They are probably a Molex connector of some type. You generally need the exact part number. You might take a look at
www.digikey.com and
www.mouser.com.
You probably won't find them with wires attached. You usually have to purchase the housing and the pins separately and assemble it yourself.
Perhaps you can find a defunct battery that you can cut the old connector and wires off. Maybe a neighbor or a yard sale or perhaps a shop that sells the batteries.