Abstract: Shared electric bikes are equipped with operation data collection and cloud recording functions, and revealing the laws of how this cloud data changes with the fire location and ignition mode can provide new evidence for the identification of fire cause and product quality management. In this paper, the characteristics and variation rules of V-t curve of the cloud data during the combustion process of shared electric bikes are studied through experiments involving open flame ignition, thermal runaway of the power battery, and electrical circuit short-circuit faults. The results show that: Open flame and short-circuit first cause the data transmission line to be disconnected, and the vehicle's voltage data drops to zero rapidly after diving, with a rate of voltage decline exceeding 500.56 mV/s; After thermal runaway of the power battery, the vehicle's voltage data drops slowly after diving, with a voltage decline rate of 20.02 mV/s, and a short-term voltage rebound phenomenon occurs during the decline; When conducting fire investigation on shared electric bikes, clues for the identification of the cause of fire can be provided by retrieving cloud data and analyzing the V-t curve characteristics.

Key words: shared electric bike, cloud data, fire cause, fire investigation