Under the premise of not affecting the battery capacity, the lithium iron phosphate battery can meet the needs of high-current charging and discharging, and solve the problem of excessive battery capacity loss when the traditional lead-acid battery is discharged at a high current. In the case of the same capacity, the high-current output energy of the lithium iron phosphate battery is about twice that of the lead-acid battery. If the lithium iron phosphate battery is used to replace the lead-acid battery in the power backup UPS, its capacity will be reduced by 50%.