However, some Chinese suppliers cheat and skimp on the electrical safety components that monitor charging conditions on the battery. So if sensors that detect battery cell temperature are inferior or missing, it won't shut off the electricity causing the cells to overheat and rupture. Some e-bike batteries are completely missing the safety components. Buy from a reputable e-bike manufacturer, and don't buy cheap replacement battery packs (there is a reason why cheap clones cost a quarter of the oem pack).
As a long-time RC modeller who watched the sometimes fiery introduction of li-poly battery technology, I agree in principle, but in practice I don’t see problems with the 2 amp charging rate of the roughly 18 amp hour li-ion battery that my bike and similar setups use. A higher charging rate without properly engineered and implemnted battery management system IS asking for trouble.