Whether it is an energy storage system or a UPS, people are accustomed to connecting two sets of batteries in parallel to one device. This is a common practice for lead-acid batteries.

　　Parallel battery packs can increase the energy of the system, and some occasions do need to connect battery packs in parallel. When selecting two sets of batteries in parallel, it should be noted that the batches are the same, the specifications are the same, and the models are the same.

　　Because the internal resistance of each battery is different, this will cause the actual output power of each battery to be different during the charging or discharging process.

　　This situation may cause the group of batteries with low charging current to be often under-charged.

　　Long-term failure to obtain a suitable charging current will increase the internal resistance of the battery. The greater the internal resistance, the smaller the charging current. This will cause a vicious cycle and ultimately lead to a greatly shortened life of the entire battery pack.

　　Therefore, when one lithium battery pack can be used to meet the needs of the equipment, two sets of lithium battery packs must not be used in parallel.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect replacement for lead-acid batteries, and they are the first choice for grid-connected peak shaving, off-grid energy storage, photovoltaic energy storage, UPS, data center and other industries.

　　As the power of electronic devices increases, there are more and more battery packs connected in parallel. I hope you can have a clear idea about this.