DIY conversion kit on an existing bike

Certified, inspected or built to a recognized fire-safety standard: Poor. London Fire Brigade states that with conversion kits, "the battery and charger may be purchased separately, sometimes from different sellers," which "increases the risk of incompatible equipment being used," that "batteries purchased online may not meet UK safety regulations and are more likely to fail," and that "DIY installations can also lead to damage of the kit, increasing the chances of battery failure and the likelihood of a fire." source↗ 2026