The design and development of a 20 kW high power density isolated dc-dc converter for an on-board battery charger is presented in this paper. The utilization of low inductive SiC power modules along with compact, low profile magnetics helps in achieving a very high power density for the 20 kW isolated dc-dc converter. The switching frequency of the converter is selected as 100 kHz. The efficiency of the 20 kW, 100 kHz isolated dc-dc converter using SiC power module is estimated above 98% over a wide range of output power. The challenges in the design of a low-inductive SiC power module is also discussed in this paper. Furthermore, the design and analysis of low profile, high efficiency magnetics is discussed along with the experimental verification of the results. The proposed 20 kW converter has a power density of 13.3 kW/L excluding the heatsink.