Construction And Failure Mechanism Of Lithium Iron Phosphate Back-up Battery System For Communication

The rise of the application of global mobile Internet promotes the construction of mobile communication base station.In order to ensure that the base station can operate normally when the power is cut off,the standby power supply is needed.The use of more traditional valve controlled sealed lead-acid battery,which has a greater pollution of the environment,and the installation is not convenient.The novel lithium iron phosphate single cell has the advantages of small size,high specific energy,high working voltage,long cycle life,and is suitable for being used as a backup battery for communication.However,in the process of practical application of the lithium iron phosphate battery,it is necessary to solve the problem of system matching and battery management.The according to the use requirements and characteristics of mobile communication base station,build the lithium iron phosphate battery backup system,study on the failure behavior of lithium iron phosphate battery,discusses the failure mechanism is proposed to avoid the failure of the battery management solution.Through the performance test of lithium iron phosphate lithium battery,it is found that the specific energy of lithium iron phosphate is 3 times as high as 120Wh/kg,which has excellent high temperature performance and safety.In the process of making the process,the environmental humidity control is less than 2%,the cycle life of the lithium iron phosphate single cell can be more than 2000 times.Over charging of lithium iron phosphate single cell damage is greater,the capacity of the battery is decreased by 30%.Lithium iron phosphate backup battery system for communication is built by using the single battery assembled by the lithium iron phosphate.According to the current output mode of the commu nication system,the two solutions are used.When the master device of communication system DC output devices,switch selection and power matching of DC rack phosphate iron lithium battery;when system main equipment AC output equipment,matched with the ups UPS-phosphoric acid iron lithium battery system.For battery could not be discharged,discharge is not balanced,each single battery performance inconsistencies by charging and discharging method of failure behavior of the lithium iron phosphate battery,lithium iron phosphate battery materials and pole piece of water will lead to the battery itself self discharge and other undesirable phenomena,in the battery manufacturing process strictly control the humidity.The failure mechanism is discussed from two aspects of the lithium iron phosphate battery and the battery management system BMS.The main reasons for the failure of the lithium iron phosphate battery for communication include: the power of the main equipment is too high,the battery is too high,and the constant pressure source has no current limiting function.The failure reason of the battery management system is the presence of AC resistance.Through the above analysis,put forward the measures to avoid the battery failure,including: timely with a small current limit(for 0.2C)for battery charging,over discharge after from time to time to wake up,the use of constant current and constant voltage power supply,increased isolation BMS communication interface.