In accordance with the invention, there is a battery defect detection method comprising applying a current ramp to a battery; determining a first time (t.sub.1) when a current of the battery reaches a maximum current (I.sub.peak), and determining a second time (t.sub.2) when a terminal voltage of the battery reaches a maximum voltage (V.sub.peak). The method also includes determining a differential (d), wherein (d)=/(t.sub.1)-(t.sub.2)/, and wherein (d) corresponds to a magnitude of defects in the battery.