13s battery wont charge to over 49v

[m3vuv]

my battery only charges to 49v then charger cuts off,its a smart bms set to static balance starting at 4v,the charger is a new 54.6v 3amp unit,any ideas what to look for,if it was a cell groupe dead i imagine i would get no power out but it still performs ok on the road but with reduced range,any ideas,bms high v cutoff s 4.2v.

 

[docw009]

Nice thing about a smart BMS is that it will show all 13 group voltages? Look at those numbers. Likely result is one or two are much lower than the others.