The current-voltage (I-V) characteristic plays a vital role in operating photovoltaic (PV) systems as it permits predicting the performance of systems and comparing the quality between different kinds of PV panels. In this paper, the analytical methods describing the I-V curves by analyzing PV model are discussed. After that, a new approach is proposed to improve the drawbacks of reviewed methods. All methods, both reviewed and proposed, extract the IV characteristic of a PV panel using only data in the data sheet provided by its manufacturer. An investigation is conducted on a multi-crystalline PV panel to verify the effectiveness between methods. The results prove the accuracy of these methods since the RMSE ranges from 0.039 A to 0.239 A. The improved method shows its reliability since the RMSE does not vary a lot when the operating conditions change. To effectively evaluate five parameters of the PV model at other temperature irradiance conditions, the proposed model and Villalva’model are applied to predict the I-V curves of PV panels with the same algorithm as the ones at the standard test condition. This suggestion proves its effectiveness when reducing a lot the RMSEs of corresponding methods.