Hybrid hydrogen storage tank is a high pressure hydrogen tank combined with metal hydrogen absorbing material to increase hydrogen mass stored per tank volume. It becomes an essential technology to supply hydrogen gas to fuel cell vehicles. However, poor heat transmission in MH bed during exoergic hydride forming reaction causes a long hydrogen charging time. This study shows basic characteristics of hydrogen charging rate and MH temperatures during hydrogen charging of a hybrid tank. Radial fin arrangement in cylindrical MH cartridge hydrogen charging enhances heat transfer in MH and reduces considerably hydrogen absorption time. The optimum fin number is also given by 2D numerical analysis.