Waydoo Charger Question

I bought a bunch of parts from a waydoo efoil including the battery and charger. I replaced the BMS in the battery and repurposed it into my first tow boogie and it works flawlessly. I hadn’t messed with using the original charger with it, but now that I built my 12s12p P45b battery, my 10a charger takes forever to charge it and I want to get this one to work with it because it’s a 50.4v 20a charger. There isn’t any problem with the charger, but it has 2 extra wires that plugged into the factory waydoo battery that I have no idea what they do. I assume they might read the battery voltage while charging for safety?? If that’s the case that’s an easy modification, but I’m not sure. Does anyone know what these two tires do? I can take whatever pics anyone needs to help just let me know what you want to see.

I can only guess but here goes:
Precharge circuit? Then would be to a resistor and then to the caps in the charger. Full voltage

a separated voltage sense like you say, if so it would go to a voltage divider and then to a microcontroller. Full voltage.

Bms communication? If so it would be at logic signal level, 3.3V or 5V

Were there any particular order that you should connect and disconnect it?

There might be a waydoo manual floating around on the web that has some charge description. I also bet it’s not a unique waydoo design, have you searched for the charger name or picture on the web?

I’ve been searching for a manual without success. I did find the manufacturer and you can get the same charger, but it doesn’t have that additional hookup. I emailed them a while ago and I never got any response. I was thinking to try the 3.3 and 5v logic and if that doesn’t work then full send with battery voltage, but I’m gonna hold off and see if anyone else has experience with it.

I bet with some high resolution pics of the pcb it would be easy for an electronics guy… but maybe even easier to send waydoo an email!

I have the quick start manual, it seems the charger is communicating

I have confirmed it’s CAN communication between the battery and charger. I wonder if there’s any way to trick it or figure out what algorithms it’s looking for. It’s seems like such a waste of a perfectly good charger.

I did the same a while ago, put a new BMS on a Waydoo battery but then used a standard charger to charge it.

Are you sure the charger is 12S not 14S?

Photos attached incase it gives you more clues.

Thank you for the pictures, it does help provide some insight. I think with knowing it is a can communication I am going to swap out my BMS with a JK smart BMS with CAN. I have the JK with uart on a couple other battery packs and they work awesome, so I’m hoping this will help solve the communication issue between the BMS and charger.