SiC has been investigated for use as a direct energy converter (DEC) for nuclear batteries. A solid-state model is being developed to calculate the electrical output of a diode into a resistively loaded circuit. This paper describes the use of a nuclear scattering code (MCNPX) to calculate the increased electron density that would be expected in a SiC material based on exposure to a Sr90 beta emitter. An incident beta (average 125 keV) generates on the order of 27k free electrons/cc per incident Sr90 electron. For each incident electron, and average of 9 keV is deposited in the SiC. The results of this effort will be fed into the Schottky device numerical model to calculate the predicted power from the device.