Early warning evaluation method for service life of battery

The invention relates to the technical field of battery health states, and discloses a battery service life early warning and evaluation method, which comprises the following steps: acquiring an initial full-charge voltage and a cut-off voltage of a battery, and selecting a first voltage and a second voltage in a range from the initial full-charge voltage to the cut-off voltage; discharging detection is repeatedly conducted on the battery, and discharging detection comprises the steps that when the battery works, a first time point and a second time point corresponding to the first voltage and the second voltage are recorded, and a time difference value is calculated according to the difference value of the first time point and the second time point; a time difference threshold ratio is preset, judgment is carried out according to the size relation between the time difference ratio and the time difference threshold ratio, and when the time difference ratio is smaller than or equal to the time difference thres