Security measure 1: Software BMS protection board, remote security monitoring

Nowadays, the domestic battery cell manufacturing level does not reach the consistency accuracy of Japan and South Korea, and the battery itself has certain safety risks. If only a pure hardware BMS board is used for protection, such electronic components have the probability of failure. Once the BMS fails, Then there will be a safety accident.

　　 Luyuan’s solution is to add a remote data transmission module to realize the data interconnection of key electrical components of the vehicle, including the charge and discharge data of the lithium-ion battery. Through the data monitoring platform of the headquarters, we can predict battery failure modes, inform users in advance and provide quick services, and eliminate potential safety hazards in the bud.

　　Safety measure 2: Improve the structure to enhance the safety of lithium-ion batteries

　　 Compared with electric vehicles, the use environment of lithium-ion batteries in electric bicycles is worse. The vehicle has poor shock absorption performance; the riding conditions are complex; the vehicle is often placed outdoors, and the battery is directly exposed to the outside, experiencing wind, sun, and rain.

　　 Luyuan independently designed a fully sealed, breathable, dry, water-proof and moisture-proof structure. The interior is filled with high thermal conductivity silica gel. While improving the seismic level of the internal batteries and BMS board, it also further strengthens the waterproof and moisture-proof performance. At the same time, it achieves the purpose of equalizing the temperature between the cells inside the battery, ensuring the consistency of the cells, and thereby improving the service life of the entire battery pack.

　　Safety measure 3: Two-way handshake recognition circuit to ensure that the battery is not used indiscriminately

　　 Electric bicycles on the market are basically straight-through output methods, which provides convenience for users to abuse batteries. For example, lithium-ion batteries are used in lead-acid vehicles, that is, lead-to-lithium sales; or used as test treasures for lead-acid vehicle trial riding; maintenance personnel may also use lead-acid controllers or chargers to replace malfunctioning lithium electric vehicles Controller and charger. These are bad habits left by the lead-acid battery era. Once the lithium-ion battery is misused on a lead-acid vehicle, the lead-acid controller has EABS reverse charging and is inconsistent with the undervoltage point of the lithium battery, which will cause safety hazards to the lithium-ion battery.

Luyuan’s countermeasure is to add a two-way handshake recognition circuit between the lithium-ion battery BMS board and the controller, and before the BMS board and the charger. As long as they do not match each other, the lithium-ion battery will close the charging and discharging circuit. Illegal controller discharging and illegal charger charging reduce lithium-ion battery safety accidents caused by external factors.

　　Lithium battery safety measure 4: PGR motor prevents reverse charging of lithium ion battery

　　 EABS reverse charging is a very good point of interest for lead-acid batteries, but for lithium-ion batteries, it has become a safety hazard.

　　 What are the hazards of reverse charging of lithium-ion batteries? We have already introduced the charging principle of lithium-ion batteries, that is, lithium ions are extracted from the positive electrode and migrate to the porous graphite negative electrode through the diaphragm and electrolyte. If the lithium ion migration speed is not fast enough and the migration amount is too large, it will stay on the surface of the negative electrode to form metallic lithium dendrites, which will pierce the diaphragm to a certain extent and cause a short-circuit explosion. The factors that affect the number and speed of lithium ion migration during the charging process are mainly the environmental temperature and the charging current.