In five years of building, selling, and repairing electric bicycles I have never, ever seen a lithium battery of any kind WITH A BMS!!!
Ever catch fire, leak, swell, or any issues of the sort.
If you use them within their designed limits and do not try to make them something they are not. They are very reliable and have no issues.
Lead Acid is dead. Time to jump ship.
96 Xr600r, 644cc 10.5:1 Je, megacycle cam/rockers, fcr41 sudco, custom exhaust and a set of 17's
<motor and frame for sale PM me