A review of light soaking of solar cells by the use of commercial IV-characterization instruments is presented. The paper addresses the challenges of studying light induced degradation (LID) using a high intensity light source. Issues related to heating of the cell, temporal intensity instability and the impact of the irradiance spectrum are discussed. The main focus of the paper is devoted to the degradation of boron-doped Czochralski silicon (Cz-Si) where boron-oxygen related complexes are responsible for a metastable defect formation. Some advantages and limitations concerning the use of IV characteristics to reveal the degradation properties of boron-doped Cz-Si compared to applying minority carrier lifetime techniques are also presented.