Defects in high quality 4H silicon carbide epilayers have been studied using Deep Level Transient Spectroscopy (DLTS) and Minority Carrier Transient Spectroscopy (MCTS). Both intrinsic defect related centers HS1, Z(1/2). EH6/EH7 and shallow and deep boron centers were found. Electrical properties of the boron related traps are analyzed. Comparison with the optical decay measurements shows that boron is related to the observed lateral variations of the minority carrier lifetime in low doped 4H-SiC epilayers.