Prediction method for battery life and apparatus for detecting battery life

The invention relates to a prediction method for battery life, wherein the method is used for predicting service life of a soft packaged lithium ion battery. The method comprises the following steps that: a functional relation between a battery capacity conversation rate and a number of times for battery charge and discharge is obtained, wherein the functional relation is expressed as: yx=a*ebx+c; besides, x is a number of times for charge and discharge and is a positive integer, yx is a battery capacity conversation rate, and a, b, and c are constant parameters correlated with the battery service life; and then according to the functional relations, the number of times for charge and discharge is calculated on the basis of a minimum capacity conservation rate. According to the invention, a capacity conservation rate of a battery is introduced into a mathematical formula to calculate a number of times of battery charge and discharge, so that the number of times of battery charge and discharge that means batte