Lead-acid safety is the danger of lithium batteries real?

A questionnaire survey was conducted on the safety of lead-acid batteries and lithium batteries. The results show that 30% of users believe that lithium batteries are more dangerous than lead-acid batteries, while nearly half of users do not have a clear understanding of the safety of the two batteries. Lithium batteries are dangerous, is this really the case? First explain one thing why the battery exploded? An explosion means an instant release of pressure. In many cases, the battery is not closed. Regardless of whether it is a lithium battery or a lead-acid battery, a safety valve will be set for the abnormal increase of internal pressure during the design. Even if there is an abnormal situation such as a short circuit inside the battery, the internal pressure will be released in time , Will not cause big risks. So since the potential risks have been considered at the beginning of the battery design, why do we often see cases of battery explosions in news reports? Most of the so-called explosions come from the capacitors of vehicle circuits or chargers. First of all, many so-called battery explosions are not actually battery explosions, but the controller or electrical system short-circuits or malfunctions that cause the capacitors to explode. There are some noises and sparks. In this case, fire is the biggest source of danger. Some capacitors explode or even open flames are not visible. Secondly, when the battery or other parts of the vehicle burn, because the body uses a large amount of plastic material, many people mistake the crackle of plastic burning as an explosion. The structure of the battery is destroyed, and the battery material explodes in the worst case after being in direct contact with the air. The battery really exploded. One situation is that the inferior battery does not have a safety valve or the safety valve is damaged, and cannot be used for pressure relief. When the internal pressure of the battery is too high, it will explode; the other situation is that the battery charger fails and the battery is overcharged. Hydrogen is precipitated inside, and deflagration occurs when the hydrogen and oxygen are mixed in a certain ratio. Lithium batteries are really more dangerous than lead-acid batteries? This is not the case. Since understanding why the battery explodes, which one is safer, lithium battery or lead-acid battery? In terms of battery structure, the current lithium battery packs are basically 18650 batteries for packaging, while lead-acid batteries are basically maintenance-free lead-acid batteries with good sealing performance. If the internal pressure is too large and the safety valve is abnormal , The risk factors of the two are basically the same. If the safety valve on the top of the 18650 battery cell is due to the overcharge of the internal hydrogen evolution, the electrolyte content in the 18650 battery is quite limited, and the amount of hydrogen evolved is also extremely limited, but for the lead-acid battery using dilute sulfuric acid as the electrolyte, if When overcharge occurs, hydrogen evolution inside the battery is serious, and the probability of deflagration is greatly increased. In the case of serious damage to a certain brand of lithium battery pack, the safety valve was activated to release the pressure, and no fire or explosion occurred. From the perspective of battery safety protection, the safety valve is designed on the 18650 battery cell, which can not only release the excessive internal pressure, but also Physically disconnecting the battery from the external circuit is equivalent to physically isolating the cell to ensure the safety of other cells in the battery pack. In addition, lithium battery packs are usually equipped with a BMS protection board, which can accurately control the state of each cell in the battery pack, and directly deal with the problem of overcharge and overdischarge from the root cause. BMS can deal with the problems of overcharge and overdischarge of lithium battery cells to the greatest extent. On the contrary, the safety protection of lead-acid batteries seems to be lackluster except for the safety valve. BMS protection is almost non-existent, and many inferior chargers can't even do it. The power is cut off after the overflow, which is far from the lithium battery in terms of safety. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: Is the price of lithium battery electrolyte wide?