Good day @sbstn, sorry for the late response.
Does the battery work?
Do you have another charger to test that battery / another battery to test the charger?
Do you have any equipment to test the output of the charger/battery?
Was the battery completely discharged? Meaning, were you testing/flying with the copter and the motors stopped responding?
Was the battery connected when you were charging it?
Did what you describe happen after a while charging or just as you connected it?