Is my battery dead?

[Frankenbike]

I’ll be quick,
Battery seems dead, charger shows green light which means fully charged.
Battery indicator shows nothing.
it’s a 48v battery but multimeter indicates 35v at battery terminals.
but the USB port on the battery works (so it looks like I’ve got a very expensive usb charger!)
Just 2 years old and not much use
Any help would be appreciated.
Thanks for reading.

 

[Nealh]

Without opening to test voltages one won't know but suspect all 13 cell goups are sub 3v or one is wya lower then the rest. 35v for a 13s battery, indicates 2.7v average per cell group. With a lot of battery BMS anything sub 3 - 3.1v won't switch to allow charging, so one will have to manually check the 13 battery cell groups for voltage.

First step is to open the battery and show pics then we can show/advise how to proceed with getting the 13 seperate group readings, not in it self a onurous task which is more then can be said for motor programming.