I have this 9Ah 42v battery pack protected by a BMS wrapped in a shrink which I would rather not disassemble (so I don't currently have access to BMS' circuit). It has two wires for charging, and two for load. Both showed 42v.
I then accidentally shorted the ones for charging for a moment (my probe melted instantly). After this incident it showed 37v. But the load wires still had 42v.
Now BMS's job is to protect battery from such occurrences. If it had a fuse, I assume it would blow thus breaking the circuit and showing 0 volts. Which must mean it doesn't have a fuse.
The battery must be okay since it still has its voltage. And its voltage reaches the charging wires in some way. But how can it change from full 42v to mere 37v? Did it have a resistor which momentarily burned thus increasing its resistance and therefore voltage drop on itself?