As noted above, there is pretty much zero chance of getting an authoritative - or even a ballpark - answer. A typical shark pack that is 36v might have a 25a peak BMS. But it could easily be less. Maybe a lot less. Especially if its some random Chinese manufacturer who built a pack for a specific ebike with God-knows-what controller in it.
The cost of getting it wrong could be the deductible on your homeowner's insurance after the resulting fire burns part of it down. My suggestion is to get a new BMS whose specs you know.