RC Submarine Charging Port

Question

I bought a cheap RC Submarine. Similar to the cheap RC Helicopters it's charged via a cable from the Remote Control. The Remote Control is powered via 6 AA Batteries. --> Here's a picture of the Charging Setup

Question: I lost the charging cable and since it's a cheap device I'm not able/willing to reorder one :-). But since I'v got the correct type of connector for the Remote Control Site, I was wondering if I can just solder one with some jumper cables that fits the port on the submarine site. If one of you could tell me of those 4 pins on the submarine is + and -. I think there are 4 Pins to submit the charging state to the remote control (light goes of if fully charged). Is it feasible to just connect two Pins (+ and -) to the charger and ignore the other two?

On the Submarine Site, the charging port consists of 4 pins. Here's a picture:

By closing the hold the pins connect as showing in the picture.

Additionally, here's a close up of the black framed part in the upper picture:

Answer 1

There's no telling the polarity of things from the connector itself, so you'll have to figure this out by e.g. measuring whatever comes out of the charger and following the lines/traces inside the submarine to the internal electrical storage.

The "black framed part" really is just a jumper: it shorts toghether the two pins it connects. My bold guess is that it's only the submarine's way of knowing you've closed the lid. (especially since the charging cable is only two wires, these two pins will probably simply be unconnected in the charging connector, but will mechanically make sure you don't connect the charging cable the wrong way around)