If you look on an external battery the ports are labeled. The two bigger poles, that are separate are the voltage feed from the external battery to the main controller. Should have a round end and a square end. The square side is + & the round side is -. Those are likely unused if that is how this company connects to the system. The other side with the 4 smaller poles is where data is exchanged and if I'm not mistaken uses Nordic uart protocol. Again there will be +/- but should have much lower voltage. Standard is +5v I believe and the communication box may have it's own lipo pack to retain communication with the company should the main battery become completely dead or box removed, but it is supplemental to the 5v coming from this port. Basically another configuration of standard usb. The other 2 poles are how data is exchanged and again should be labeled on external battery. I'm aware that you may not have access to an external pack to identify but with some savvy searching, should be able to find it. Tx = transfer and Rx is the abbreviation for prescription. That's the one you want because your scooter is obviously sick. JK. Sorry, had to.. Rx is actually, as you may have guessed by now, receive (Rx = Receive) Again, same way data is exchanged via USB. Standard serial ports for many different protocol, just arranged for this specific one, which again I believe is uart. Beyond that I don't know much more. I know that this is what would need to be hardwired in order to communicate with the controller and exchange data, but I'm sure that I'm stating the obvious because that's exactly what the primary function of the rental companys communication box is. When someone wants to rent the scooter and goes into the app, the app then talks to the scooter through this port and after verifying a list of parameters necessary to unlock. After verifying, the app will then send the unlock code to the communication device and the box well then send the information necessary to the controller on the scooter itself via this port. Essentially that is what happens on the consumer model without the rental company's box. They have it programmed to wear communication is rerouted from the power button to the serial port, it is very simple code typically just like standard operation using the power button. On the stock firmware communicating with a factory dash a single short press will turn on the unit, double short press is to toggle the different modes (red S, white S & no s or eco), single short press after the unit is turned on to toggle the headlight on and off and long press to turn off the unit. The port is just another means of doing so and essentially interrupts that circuit. That's why when the company uploads their firmware until the communication box completes the circuit after communicating with the app and verifying the parameters, the dashboard has no power and pressing the button does nothing. I have spent countless hours researching as I am lame when it comes to anyting like this. Much more of a mechanical type guy then and electronics type guy but that's not to say that I don't enjoy messing with anything that has a motor on it and I'm always up for a good challenge. I hope this layman explanation helps, if it does and you should come across more information that would help us all achieve our end goal, please return the favor and share whatever it is you find out or any theory you may have. just the same as there's no such thing as a stupid question as long it's represented as a theory(I think..., I believe..., Etc) there are no stupid hypothesis. After all, people exchanging ideas, spitballing or whatever you want to call it what's likely the origin of this whole scooter share concept. It took a collaboration of businessmen, electronic gurus and ground-level grunts to assemble the product that we are trying to dissect ourselves. To assume that one person could crack the code that took so many to put together would be silly. So, we need each other as I assume others have figured this out using information on here but never returned afterward to share their findings having achieved their goal and no longer needing the information on this board. One love, power to the people To view images REGISTER or LOGIN for full access.