The present technology provides a method of detecting a battery cell having a low voltage defect, including: setting a reference time point when a voltage of a battery is stabilized after a shipping charge, and measuring a first voltage of a battery cell at the reference time point; measuring a second voltage of the battery cell with a temporal interval longer than a period at which a self discharge of the battery cell is suppressed; and determining whether the battery cell has a low voltage defect by comparing a difference (ΔOCV) between the first voltage and the second voltage with a reference value, wherein the reference value is +3 sigma (σ) to +6 sigma (σ) in a normal distribution of a voltage drop amount obtained by the measuring of the first voltage and the measuring of the second voltage for a plurality of normal sample battery cell groups.