Depending on the Charger, in my case a Passport ultra, it has 2 styles of connector from the factory, but you can buy 8 ot 10 different ones taht simply plug into the 2 pole Molex plug..
I had to buy a adapter with a blue EC3 end on it, too bad sold out So i had to options to make one. either get a female molex, female ec3 some wire and get hot soldering OR
banana plugs and blue EC3 connector. I built the Banana version.. these 2 links show the two options i had..
and the option i chose