Why can't new and old UPS batteries be mixed and matched?

Why can't the new and old UPS batteries be mixed and matched because the new UPS battery contains more chemical reaction substances, higher terminal voltage, and lower internal resistance (the internal resistance of the new 12V UPS battery is only 0.015-0.018); while the old UPS battery terminal voltage is relatively high Low and large internal resistance (the internal resistance of the 12V old UPS battery is above 0.085). If the new and old UPS batteries are mixed in series, the charging voltage at both ends of the old UPS battery will be higher than the charging voltage at both ends of the new UPS battery in the charging state. As a result, the new UPS battery is not fully charged and the old UPS battery is already charged too high. ; In the discharging state, because the charge capacity of the new UPS battery is larger than that of the old UPS battery, the result is that the old UPS battery is over-discharged, and even the old UPS battery is reversed. The capacity of the battery inside the old UPS has been reduced. If mixed use occurs, firstly, the internal resistance of the power supply will be added, which will reduce the system efficiency of the entire battery pack and the external output; secondly, it may cause the battery itself to heat up or even explode. As an emergency, do not mix UPS batteries with different internal electrolytes. UPS batteries with different charge capacities cannot be mixed in series. When using them in series, if they are connected in series, the battery with low internal resistance and low potential may be over-discharged, and the stock will be exhausted at a time, and the internal current will exceed the allowable value, which will cause rapid aging. , Scrapped, at this time the new battery in the battery pack will also be dragged down, and there will be chain reactions. If it is connected in parallel, the internal circulation of the battery pack will occur. On the one hand, the external output will be weakened, and on the other hand, it may cause the battery itself to heat up or even explode. Even in emergency use, do not mix batteries with different internal electrolytes, such as rechargeable batteries and alkaline batteries. Mixed use of batteries is very dangerous. Correct UPS battery usage method. In fact, based on the principle and related experience, we generally recommend using UPS batteries with a unit of 24AH or more. If you find that a single battery is in bad condition after using for less than one year, it is recommended to replace only a single fault. If there are multiple batteries in the whole group that are defective, it is recommended to replace all the batteries in the whole group; second, if the battery pack has been used for many years, or is close to the service life (lifetime), the battery life will be shortened, and some of the batteries are abnormal , It is recommended to directly replace the entire set of batteries, this is the best solution, remember not to use refueling tactics, and constantly replace the faulty batteries. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous article: How to maintain and maintain the 12V lithium iron phosphate battery pack?