The invention discloses a novel detection method for self-
discharge characteristics of
lithium iron phosphate system power
lithium ion batteries. The method comprises the following steps: step 1, charging and discharging batteries, and adjusting SOC (
System On
Chip) states of the batteries to be 20-40%; step 2, standing for a certain period of time at normal temperature, and measuring open-circuit
voltage (OCV)1 of the batteries; step 3, performing high-temperature aging on the batteries; step 4, standing for a certain period of time at normal temperature, and then detecting OCV2 of the batteries; step 5, calculating a
voltage drop deltaU of the batteries, wherein deltaU is equal to OCV1-OCV2; and step 6, calculating an average value and standard deviations of the
voltage drops of the same group of batteries, determining a self-
discharge detection standard of the batteries, and screening. The method for detecting the self-
discharge characteristics of the batteries by virtue of voltage differences of the batteries disclosed by the invention can be used for well shielding interference of factors such as equipment, operations and environment temperature existing in a manufacturing process of the batteries in the self-
discharge data acquisition accuracy of the batteries, so that the self-discharge characteristic data
distortion of a single battery can be avoided, the matching reliability of the batteries can be effectively improved, and the cycle life of a
battery pack can be prolonged.