Pedelec battery BMS

[HansGruber]

I am trying to repair this battery for a pedelec:
https://www.batteries4pro.com/en/Mobility/electric-bike/3,17085-battery-36v-145ah-yamaha-winora-y280-type-li-ion-x-haibike-sduro-3052351243985.html

The battery is from a colleague and he told me that the battery gauge LEDs always indicates that the battery is fully charged. After inserting the battery, the pedelec does not accept it. That's all the information that I have.

After opening the thing up I saw something very obvious, at the 10S balance charge connector the two highest voltage rails shorted at the connector. Removing the cable destroyed the connector since it was secured with some goo, but it's donzo anyways.

Here is the BMS without my comments: https://imgur.com/a/y9eDvYd
Please look into the image with my comments here.

My plan is to completely remove the connector and solder the cables directly to the B1-B10 testpoints. I measure the individual voltages of the 10S cable, I've noted it in my comments. Can someone tell me if the cells are still good with these values ? It's 37,8V for a 36V battery. I've also measured all the powerrails I could find. They all seem to be okay 13V, 5V, 2.5V. The LED gauge shows 2/5 LEDs (now, after restarting it) for 37,8V with disconnected 10S cable, is that plausible ?

My biggest concern is that the internal battery voltage is 37,8V but I only measure 15,5V on the connector to the pedelec. There is also a communication line between the power lines. Will it negotiate the voltage with the pedelec ? If not, I am not sure what could cause the voltage drop. Maybe someone has better knowledge how these things work.