The concept of directly collecting secondary electrons created by beta emission through an electrical insulator has been proposed as an attractive low-voltage nuclear battery termed a secondary emission cell (SEC). In this paper, a MATLAB computer simulation of an SEC is conducted using Mott scattering, the Penfold-Katz slowing approximation, Bethe's ionization loss expression, and energy and momentum conservation. The goal of the simulation is to compare the efficiency of an SEC to that of a vacuum direct collection cell. It is found that the SEC efficiency is typically <= 1%. Energy losses in the insulator prevent it from having an efficiency advantage over a vacuum direct collection cell which offers higher efficiencies, especially at high voltages. However, operational simplicity and ease of construction still make the SEC attractive for some applications.