The paper presents an approach to increasing the reliability of a nanosatellite EPS (Electrical Power System) while expanding upon its functionality. The approach is split into three different categories, which include: replacing complex integrated circuit components with circuits of analog components, changing the architecture of the subsystem to rely on a protected FPGA and finally using a combination of the two to implement protection functionality of the EPS system. These methods were applied during the design of the TRISAT satellite EPS. Specifically, the introduction of an Analog Maximum Power Point Tracking circuit and a Transformer Coupled Charge Sharing battery balancer using LiFePO4 battery cells to the EPS power generation and storage is presented. Additionally, the use of Latching Current Limiters for both, protection of EPS functionality as well as for power distribution is shown. Finally, methods to protect the FPGA circuit itself, using a combination of careful logic design based on a TMR method, coupled with external circuitry are demonstrated.